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|Table of Contents|
Glossary of soil terms
Front Matter 1
Front Matter 2
Table of Contents
Fertility, management, and plant growth
Organic matter, mulches, and composts
Moisture and temperature
Testing and control of acidity
Hunger signs in garden plants
Friendly organisms and their care
Harmful organisms and their control
SOIL TERMS X
ACTINOMYCETES. A group of soil microorganisms producing an extensive
threadlike network of mycelia. Although these microorganisms resemble
soil molds in some respects, they are more like bacteria in size. They
thrive in sweet soils that are well aerated.
AERATION, SOIL. The exchange of air in soil with air from the atmos-
phere. The composition of air in a well-aerated soil is similar to that in
the atmcsi here. In a poorly aerated soil, the air is considerably higher
in carl' n dioxide and lower in oxygen than the atmosphere above.
AIR-DRY SOIL. Soil that is dried in the open atmosphere. Air-dry soil
will have a niall moisture content controlled by the hurmrdity.
AMMONIFICATILN. Formation of ammonium compounds ia soils by
AVAILABLE NUTRIENTS. The part of the supply of a plant nutrient in
the soil that can be taken up by plants at rates and in amounts signifi-
cant to plant growth.
BOG SOILS. Soils developed under swamp or marsh types of vegetation,
mostly in a humid or subhumid climate.
CALCAREOUS SOIL. Soils high in calcium carbonate (often with mag-
nesium carbonate) having an alkaline reaction due to the presence of
free calcium carbonate.
CATENA, SOIL. A group of soils within a specific soil zone. Although
formed from similar parent material, they are unlike because of drain-
age and slope.
CHELATE. Organic compounds that combine with iron and other heavy
metals (most of which are minor elements), holding them in such a
way that, when in contact with the soil, they are released slowly. These
chelated elements are not fixed or made unavailable when in contact
with other chemical compounds in the soil.
CLEANED TILLED. This refers to row crops that are cultivated in be-
tween the rows, such as corn, beans, etc. The soil is kept stirred and
free of weed growth.
COLLOID, SOIL. A term used with reference to matter, both inorganic
and organic. Colloidal particles, microscopic in size, have a large sur-
face area per unit mass. Many mineral soil colloids are actually tiny
crystals. Under certain conditions, soil colloids form a more or less stable
suspension or dispersion in water. Membranes allowing the passage of
chemical ions are too small for the passage of colloidal particles.
CONTOUR FuRRows. Furrows plowed at right angles to the direction of
a slope. These furrows, level from one end to the other, are used to les-
sen runoff of surface water.
DECOMPOSITION, SOIL. The destruction of plant and animal remains by
soil microorganisms for the purpose of supplying food, energy, and tis-
sue building material for their life needs. Remains of both decomposed
material and living and dead microbial cells constitute organic matter
of the soil.
DUFF. The surface layer of organic matter in forest soils. This mat or
surface litter is only slightly decomposed.
FOLIAR FEEDING. A method of fertilizing plants by spraying fertilizer
in solution form over the foliage.
FRIABLE. Easily crumbled in the fingers; nonplastic.
GERMINATION. The sprouting of seeds or microbial spores in the soil.
HARDPAN. A hardened or cemented soil horizon.
HEAVY SOIL. Soils containing large amounts of silt and clay. The term
refers to the difficulty of working this type of soil and not to actual
HORIZON, SOIL. A layer of soil, with more or less well-defined character-
istics, approximately parallel to the surface of the land. These charac-
teristics have developed through normal weathering processes.
LATERAL FEEDING ROOTS. Any of those plant roots extending out from
the plant at right angles, parallel to the soil surface. Generally, the ma-
jority of feeding roots are found near the surface of the soil.
LEACHING. Removal of materials in solution, such as the removal of
plant food elements in the soil solution, by leaching rains.
LEGUME. Any of those plants, both cultivated and wild, bearing their
seeds in pods, and having legume bacteria nodulation on their roots.
Because of their ability to remove nitrogen from the air and add it to
their tissue-building process, these highly prized plants are used for food
and green manure crops. The protein content of legumes is higher than
most cultivated plants. Rhizobium bacteria, living symbiotically with the
plant and making their home on its roots, are able to fix free nitrogen
from the atmosphere, thereby supplying it to both themselves and the
LIGHT SOILS. This term indicates that the soil is sandy in nature and is
MICROBE. A common term given to soil microorganisms or living or-
ganisms in the soil that cannot be seen with the unaided eye.
CONTINUED ON REAR ENDLEAVES
x 500 X
x Answers x
SETON N. EDSON
UNIVERSITY OF FLORIDA PRESS
A University of Florida Press Book
KNOW YOUR FLORIDA SERIES
COPYRIGHT( 1963 BY THE BOARD OF COMMISSIONERS
OF STATE INSTITUTIONS OF FLORIDA
All rights reserved. No part of this book may be reproduced in any form
without permission in writing from the publisher, except by a reviewer
who wishes to quote brief passages in connection with a review written
for inclusion in magazines or newspapers.
Library of Congress Catalogue Card No.: 63-21504
PRINTED BY THE MILLER PRESS, JACKSONVILLE, FLORIDA
BOUND BY UNIVERSAL DIXIE BINDERY, JACKSONVILLE, FLORIDA
F LORIDA HOMEOWNERS have come to the Sun-
shine State from all parts of the nation. Almost
without exception, they are at a loss to know how
S to manage the soil they acquire here, soils so
different from those back home. Most will have to develop com-
pletely new concepts of soil management and, in so doing, need
guidance. Now, in YOUR FLORIDA GARDEN SOILS, Floridians
have a dependable guide-book. Over five-hundred questions and
answers on soil types, reaction, soil improvement, fertilization,
drainage, and irrigation most frequently asked by Florida home-
owners make up this guide.
Answers were written by Seton N. Edson, Associate Professor
of Soils at the University of Florida, who has had long experience
as a university teacher, county agricultural agent, lecturer, award-
winning researcher, and home gardener. His simple, lucid an-
swers are based upon latest findings in research laboratories, as
well as upon tried and true practices that have stood the test of
YOUR FLORIDA GARDEN SOILS: 500 QUESTIONS AND AN-
SWERS, an addition to the KNOW YOUR FLORIDA SERIES, is most
warmly commended to all who garden in the Sunshine State.
November 25, 1963
JOHN V. WATKINS
University of Florida
Glossary of Soil Terms FRONT EN
Foreword by JOHN V. WATKINS
Illustrations and Charts
1. Florida's Soils
3. Fertility, Management, and Plant Growth
4. Organic Matter, Mulches, and Composts
5. Moisture and Temperature
72 Testing and Control of Acidity
8. Hunger Signs in Garden Plants
9. Friendly Organisms and Their Care
10. Harmful Organisms and Their Control
Glossary of Soil Terms (continued) REAR EN:
Soil Profile 2
Familiar Names of Florida Soils 8
Central Florida Drainage Catena 10
Soil and Water Losses 22
Fertilizer Placement 34
Fertilizing a Shade Tree 38
Making Seed Furrow and Covering Fertilizer 45
A Practical Compost Bin 64
A Superior Potting Mix 66
The Moisture Cycle 80
Use a Good Mechanical Sprinkler 82
Taking a Soil Sample 104
Reading the pH Scale 109
Typical Iron Deficiency Symptoms 118
The Essential Elements for Plant Growth 123
HOW TO MAKE AND USE YOUR OWN SOIL ACIDITY
TESTING EQUIPMENT 143
SUGGESTED AMOUNTS OF FERTILIZERS FOR
FLORIDA GARDENS 144
APPROXIMATE AMOUNTS OF PURE GROUND AGRI-
CULTURAL LIMESTONE REQUIRED TO RAISE
THE pH VALUE FOR DIFFERENT SOILS 144
pH PREFERENCE FOR GARDEN PLANTS 145
A .S WE ARE WELL AWARE, the importance of
A soil and its care are basic to plant growth-in-
deed for life itself. Becoming acquainted with
the soil in one's own area is a prime requisite in
making the most of a home garden. Failure to understand it,
because of lack of knowledge of soil management, climatic condi-
tions, disease, and insect problems lays the foundation for hun-
dreds of questions.
Florida's sunshine and healthful climate have filled its borders
with residents from every corner of our continent. Many of these
new citizens, among them the retired, want to try their luck at
gardening. Along with many of its native residents, they do not
realize the profound differences that exist between soils of Florida
and soils found in other parts of the nation. Without some knowl-
edge of conditions prevailing, their efforts soon result in failure
For the last twelve years, the author has received countless
questions concerning Florida soils from agricultural workers, home
gardeners, vocational teachers, county agents, students, and others.
From these inquiries he has compiled over 500 of the most fre-
quently asked questions which should appeal to the home gar-
dener. Accurate answers to many of them are not easily found.
Therefore, to fulfill the need for answers under one cover, YOUR
FLORIDA GARDEN SOILS: 500 QUESTIONS AND ANSWERS, was
written. To enable the average gardener to understand without
difficulty, questions and answers are kept in simple terms, with
attention focused on home garden conditions. For further answers
and excellent reading, numerous references are given to material
available from the County Agricultural Agent's Office, the Uni-
versity of Florida Agricultural Extension Service, and state and
federal agricultural bulletins.
The author is indebted to his associates of the College of Ag-
riculture, University of Florida, and to Florida's County Agricul-
tural Agents for their assistance in developing this book. Useful
suggestions and comments were provided by Dr. F. B. Smith,
Head of the Department of Soils, Dr. George D. Thornton, As-
sistant Dean, College of Agriculture, Dr. 0. C. Ruelke, Assistant
Professor of Agronomy, Soil Surveyor Ralph G. Leighty, and
Professor John V. Watkins, who read and criticized various chap-
ters in the book. Special recognition is given to Mr. Tom Lay for
his excellent illustrations and to the author's wife, Margaret, who
served as consultant, critic, and proofreader.
Gainesville, Florida SETON N. EDSON
June 1, 1963
Q.-Is it true that brown subsoils are always acid?
The color of soil is not a good indicator of soil acidity. Black,
gray, yellow, red, or brown soils may be either acid or alkaline,
depending on the material from which they are weathered and
their content of organic matter. Other environmental effects may
also influence the degree of acidity of soils.
Q.-Should I cultivate or spade a wet clay soil?
Never cultivate or spade a wet clay soil. Clay soils that are
worked while they are wet become puddled, the fine particles
running together, causing destruction of the soil structure. A
good time to spade or cultivate a clay soil is when it feels moist
and crumbles easily when pressed in the hand.
Q.-What can be done to clay soils to improve root development?
Root development can be improved in clay soils by planting and
turning under green manure crops, preferably legumes or any
organic material, and by deep plowing or tillage after the soil
has drained thoroughly following a rain.
FLORIDA'S SOILS 3
Q.-What is a soil profile?
When a vertical cut is made into the soil so that distinct layers,
parallel to the surface, are observed, the combination of these
layers (horizons) constitutes the soil profile. Generally, soil pro-
files extend downward to depths of 20 to 60 in.
Q.-Since the addition of organic matter improves a sandy soil,
will the addition of organic matter also improve a clay soil?
A clay soil that is low in organic matter will be improved by its
addition. The main improvement will be the superior tilth of the
soil and the addition of some organic nitrogen.
Q.-What is a marl soil?
Marl is a crumbly deposit consisting mainly of clay mixed with
calcium carbonate. In Florida, shelly marl is derived from marine
shell deposits. Sometimes Florida marls are covered with a thin
or thick layer of acid sands.
Q.-Are all black soils the most fertile soils?
Not necessarily. For most of Florida's black sandy soils, it is often
necessary to add most of the minor elements as well as a high
amount of phosphorus and potassium as fertilizers. The reason
black soils are often termed fertile, or rich, is that there is a
rather high content of organic nitrogen present in these soils.
The tilth or structure of these soils is also improved by the high
content of organic matter.
Q.-I have heard our County Agricultural Agent speak of a Leon
fine sand. What kind of soil is this?
Leon fine sand is the official name of one of several soils occur-
ring in flatwoods areas. These soils are acid, somewhat poorly
drained, have a black or dark brown organic pan relatively near
the surface, and support a native growth of pine trees and pal-
Q.-I have a heavy clay soil. Will the mixing of sand with this
soil improve its tilth?
Yes, for small areas, where cost and time are not important fac-
tors. However, the turning under or mixing of organic material
may be more beneficial.
Q.-The surface soil has been removed from the area where I
wish to locate my garden. Can I improve the present sur-
Probably the most important material lost in the removal of the
surface soils is the organic matter. By planting and turning under
suitable green manure crops, as well as any other plant residues,
the organic matter can be replenished or increased.
Q. -Should I use a special fertilizer for marl soil?
Certain minor or trace elements often become deficient in marl
soils which have a pH above 7. The general practice is to use a
mixed fertilizer with the addition of a minor element spray. The
spray is applied over the leaves of the plant when a deficiency is
Q.-Is the subsoil a useless part of my garden soil?
The subsoil is a necessary part of garden soil. Among other things,
the subsoil is a storehouse for soil moisture, helping to retard the
loss by leaching of valuable plant food elements.
Q.-What is a virgin soil?
This generally refers to a soil that has its native growth of vegeta-
tion undisturbed by cultivation.
Q.-What is the difference between a sandy loam and a loamy
Sandy loam and loamy sand are textural class names. A sandy
loam is a soil consisting largely of sand but having enough silt
and clay present to give a small amount of stability. If squeezed
when moist, it will form a cast that will withstand careful han-
dling without breaking. A loamy sand contains less amounts of
silt and clay and has less stability when squeezed than a sandy
YOUR FLORIDA GARDEN SOILS
FLORIDA'S SOILS 5
Q. -Would it help if I had a layer of topsoil hauled in and spread
over my sandy lot?
Spreading a layer of topsoil over sandy soil on a small lot should
be helpful, especially as an aid in the retention of soil moisture.
On large sandy lots, however, the cost may be prohibitive. One
should also consider the losses of organic material in the topsoil
by microbial oxidation. In Florida the rate of oxidation is very
Q.-What are some characteristics of a good garden soil?
A good garden soil should have the following characteristics:
1. Soil type: A medium-textured soil. The clay content should
be high enough so that moisture and plant nutrients are re-
tained, and not too high in moisture so that the soil is easily
2. Soil reaction: The lime content of the soil should maintain
a pH of about 6 to 7.
3. Moisture: Irrigation, drainage, and soil texture should all be
considered in the moisture control of the garden soil.
4. Organic matter: To support good biological activity, the or-
ganic matter content should be between 3 and 4 per cent by
Q.-Should I be careful in selecting the correct type of soil for
planting my pecan trees?
This is one instance where the type of soil has a profound effect
on plant growth. Pecans grown on soils with a pan, such as Leon
fine sand, will become stunted and finally die, probably due to a
shallow water table level. Pecan trees have a deep root system
and demand a fertile, deep, medium-textured, well-drained soil.
Q. -Does the type of soil make any difference as to how deep or
how widely spaced seeds should be planted?
The depth and spacing of seed will depend on both the soil type
and the kind of plant the seed represents. For example, corn seed
would be spaced farther apart on sandy soils to prevent too much
6 YOUR FLORIDA GARDEN SOILS
competition for fertilizer and moisture. Perhaps corn would also
be planted a little deeper in the sandy soils to secure a better
Q. -Why does my soil dry out so quickly after a shower of rain?
The coarser the soil, the quicker it will dry out after a rain. Fine-
textured soils having a high content of clay and humus hold more
of the rain water that falls on them, and thus dry out slowly.
Q.-What are some ways of improving a poor soil?
The best way to answer this question is in steps, as follows:
1. Check the drainage or irrigation problem and make any im-
2. Apply dolomitic limestone if needed.
3. Maintain the existing organic matter content of the soil with
a selected cover crop.
4. Apply the recommended kind and amount of a complete
5. Have a good program of weed and pest control.
Q.-I have a spot in my garden that is said to be "sand-soaked."
What does this mean?
When the geological formation below a sandy soil profile sud-
denly dips downward, it allows the weathered claylike materials
to go much deeper in the sandy soil than would otherwise take
place. This leaves a very deep sandy layer that is highly leached
by rains. These areas are known as sand-soaked spots and gen-
erally support very little plant growth.
Q.-Why do plants grow better in certain spots in my garden?
One or a combination of the following factors may cause superior
growth of plants in certain spots:
1. Better light conditions.
2. Better moisture conditions.
3. Better soil fertility conditions.
4. Better biological and organic conditions.
5. Freedom from disease and pests.
FLORIDA'S SOILS 7
Q.-Are all peat soils the same?
No. The nature and kind of peat soil are determined by the plant
material from which it is derived.
Q.-Are all peat soils acid?
No. If they have developed over limestone, many peat soils are
only weakly acid or neutral in reaction. On the other hand, peat
soils that do not develop over limestone are very acid.
Q.-I am a successful grower of weeds only. What does my soil
If you can successfully grow good, healthy weeds, then the only
problem you have is to remove the weeds to prevent competition
for fertilizer and moisture by your garden plants. This requires
hand labor, which is still the best way to keep a garden free of
Q.-Why are peats and mucks so much valued for growing
Among the good and bad points in peat soils there are several
outstanding good points.
1. A very high content of organic nitrogen which is oxidized
into a steady amount of available nitrogen for rapid plant
2. A very high capacity to hold water and fertilizer.
3. A soil that is easily worked and well aerated.
4. Peat and mucks tend to make other plant nutrients more
Q.-My lawn receives a uniform application of fertilizer and
water, yet some spots are not as thrifty as others. Why is
If it is not a turf disease, it could be caused by a change in the
soil. It is not uncommon for the clay accumulation in a soil to
dip suddenly, leaving a deep layer of sand in its place. Constant
leaching leaves this area much less fertile than the surrounding
SOME FAMILIAR NAMES
OF OUR FLORIDA SOILS
I : GRAY AND BLACK FLATWOODS SOILS
___--GRAY AND BLACK FLATWOODS SOILS
2 RESTING OVER LIME MATERIALS.
3 MUCK AND PEAT SOILS
RED AND YELLOW CLAY SOILS
4= OF NORTHWEST FLORIDA
S= RED AND YELLOW SANDS OF THE
6g RED AND YELLOW SANDS OF THE
7T SWAMPS, SCRUB OR DRY SANDS
FLORIDA'S SOILS 9
Q.-Is it worth the price to remove all sand, broken block, and
debris around my new home, or is it more practical to im-
prove the soil where these are found?
Both are necessary. Remove as much of the broken blocks, lime,
and debris as possible, and then haul in a fertile mixture of peat
and topsoil and put it in their place. Acid-demanding plants need
constant attention when planted in soils with large amounts of
lime residue, such as new soil around a masonry home. Further
improvement of the soil is made by keeping a thick mulch of
leaves or pine straw around the growing shrubs.
Q.-Where did so much sand in our Florida soils come from?
Several times during the past million or so years, Florida has been
under the sea. Each time this has taken place, layers of sandy
sediments have been deposited over the marine limestone shelf.
The deposits form the familiar marine terraces or ancient beaches
which one sees when driving in an east-west direction in Florida.
Q.-I have heard that soils are classified by names. Will you
enlighten me on some of the more familiar Florida soils?
You need to know the names of the soil series and their textures.
Combined, these two aspects of soil classification constitute the
soil type. Here are the names and locations of some common
Florida soil types.
1. Lakeland fine sand: Well-drained yellow sandy soils of the
2. Leon fine sand: A somewhat poorly-drained soil of the flat-
woods, supporting saw palmettos and pine trees.
3. Red Bay loamy fine sand: A red clayey soil of northwest Flor-
4. Fellowship loamy fine sand: A phosphatic soil of the central
Q.-I have a low and wet type of soil. How can I manage such
a soil to grow fruit trees?
Your principal problem is adequate soil drainage. After a good
CENTRAL FLORIDA DRAINAGE CATENA
R'AL'R" GRAY AN..D" BLAck* :.:
;: :: :.:FLATWOODS SOILS """U"' AND1P 'I "
program of soil moisture management, you can further condition
your soil with lime, if needed, and recommended fertilizers. It is
desirable to have adequate drainage to a depth of 36 to 48 in.
for citrus and other fruit trees.
Q.-Should I set plants directly into newly-excavated or dredged
soil without further attention?
Most excavated soils are lacking in organic matter and, thus,
lacking in enough nitrogen as well as other elements supplied in
whole or part by the soil humus. A fertile mixture of peat and
topsoil should be added to the hole prior to planting.
Q.-Will pine trees grow on soils with a hard pan?
Yes. Most of the soils of Florida's flatwoods have an organic pan,
and many of these soils do support a growth of pine trees. These
soils also have a shallow water table which restricts the penetra-
tion of roots.
Q.-Should I make any attempt to fit certain plants to certain
On large areas of specific soil types it is wise to consider the crop
or plant that is best suited for the soil. For small areas, however,
the soil is often man-made to fit the plant. For example, a Leon
fine sand would not be recommended for growing fruit trees un-
less adequate drainage is provided.
Q.-What causes a hardpan and what is it composed of?
The constant percolation of rain water through the surface soil
carries with it very fine materials that may be deposited either
shallow or deep within the soil, depending on local conditions.
The most common soil materials that form hardpans are oxides
of iron and aluminum, clays, organic matter, or mixtures of any
Q.-Should my garden be planted on high or on low ground?
If you have a choice of either high or low ground for your garden,
the primary consideration should be the soil moisture conditions.
YOUR FLORIDA GARDEN SOILS
If the garden site is too low, it may be too wet and therefore dif-
ficult to drain properly. If the garden site is too high and the soil
is sandy, it may be too drought for a successful garden. A good
garden site should have some of both-good soil aeration and
good soil moisture conditions.
Q.-Can I improve a highly-leached sandy soil?
This would first depend on how the sandy soil became highly
leached. If it were caused by the continual removal or burning
of plant residues, then this soil could be improved by growing
and turning under of plant residues. If this is a virgin soil, then
the organic matter content will tend to remain fairly constant. In
either case, the addition of a balanced mixed fertilizer in split
applications during the growing season is a beneficial practice for
highly-leached sandy soils.
Q.-Does a hardpan affect the growth of citrus trees?
As citrus trees have a deep taproot, they do not do well on soils
with a hardpan for this reason: Soils with an organic pan usually
have a fluctuating shallow to moderately deep water table which
restricts the depth of rooting of the citrus trees.
Q.-Can the native growth help indicate the kind of soil to be
expected in that area?
There is a distinct relation between native growth and a virgin
soil type. A thorough study of this situation can be made by
using a County Soil Survey report and map as a field guide. For
example, in central Florida, soils under turkey oak are acid,
excessively-drained yellow sands. The most common soil type is
Lakeland fine sand.
Q.-What kind of soil is best for roses?
It has been found that acid soils, with a fair amount of clay close
to the surface, favor the growth of roses. Since roses are grown
in small beds or by themselves, it is economical to make a man-
made soil with sand, organic matter, and clay. The kind of roses
and the location of the site will determine the amounts to mix.
FLORIDA S SOILS
Q.-I have a large garden area. Is there any advantage in using
a County Soil Survey map to plan my garden?
Besides locating the soil type for your garden, there are several
advantages in using a County Soil Survey map. You will discover
considerable information about your county that you may not
have known. In addition to climatic and vegetative information
that will broaden your knowledge of county soils, you will find
a careful description of soil types or phases in your garden area.
Q.-What is a loam soil and why is it valued so highly?
A loam soil is generally considered to be a soil with an ideal
texture. Loams have about equal amounts of fine and coarse soil
particles. This, in turn, promotes better aeration, ease of culti-
vation, and good moisture retention.
Q.-I have a sandy soil, but it is very black. How did so much
organic matter accumulate in this sand?
In Florida the black sandy soils are caused by a combination
of abundant vegetative growth and usually a high water table.
Water that stands above the surface of the land for long periods
of time causes anaerobic activity, or lack of sufficient air for
rapid oxidation of the plant residues. Thus, over long periods
of time, this partially-decayed plant material accumulates and
causes the dark colors.
Q. -My garden is located only a few miles from a large lime-
stone mining operation, yet I am told that my soil needs
lime. Why is this?
The entire state of Florida is underlain with marine limestone.
In some areas it dips deep below the surface; in other areas, it
is exposed at the surface. This variation can be abrupt, leaving
acid sands only a short distance from limestone outcropping.
Leaching rains tend to make this situation more pronounced.
Q.-Does Florida have any of the "red clay soils" so often seen
in the Southeast?
Soil types have no respect for county or state borders. Large
YOUR FLORIDA GARDEN SOILS
areas of typical red clay soils extend across the Georgia and Ala-
bama borders into the northern counties of Florida.
Q.-What are Florida hammock soils and why are they different
from other soils?
Hammock soils commonly refer to soils supporting a natural
growth of live, laurel, and other oaks, magnolia, hickory, gum,
and other hardwood trees. In southern Florida, cabbage pal-
mettos are included in the hammocks. These soils, unique in
Florida, are influenced by outcroppings of phosphatic limestone.
Most hammock soils are considered medium fertile. They are
found in large areas of Alachua and Marion counties.
Q.-What is the difference between peat soil and muck soil?
The difference between peat soil and muck soil is dependent on
the degree of decomposition of the plant material from which
they are derived. The fibers of plant material can still be recog-
nized in peats but cannot be identified in mucks. Muck is gen-
erally decomposed to a distinct black color, whereas peat may
still be quite brown in color.
Q.-What are the scrub and turkey oak soils of Florida used for?
Where they are sufficiently frost-free, they are highly prized for
citrus culture. When these sands cannot be used for citrus, they
are generally left in their native growth of scrub and turkey oak.
Q.-What material in the soil helps prevent leaching of ferti-
The principal materials in soil that help prevent leaching of
fertilizers are the fine colloidal particles. These may be clays,
organic matter, or both.
Q.-Can I use a very sandy soil for gardening?
If very sandy soil is your only choice for a garden spot, then
sandy soil it must be. By giving careful consideration to moisture
and fertilizer problems, you can use this type of soil for garden-
ing. Contact your local County Agricultural Agent for specific
management and fertilizer practices.
Q.-What are the "scrub oak soils" of Florida?
Scrub oak soils generally refer to soils supporting a natural growth
of scrub live oaks, turkey oaks, and usually some sand pine, rose-
mary, runner oak, prickly pear cactus, saw palmetto, and wire-
grass. The soils are usually excessively drained, highly leached,
and low in natural fertility. The surface soil consists of thin,
light gray, or gray sandy materials. It is underlain by white sandy
horizons to a depth of 60 in. or more, or the white sands may
be underlain by yellow sands at depths of 10 to 30 in.
Q. -Does the type of soil have any effect on the amount of
water used for irrigation?
Very much so. The finer the texture of the soil, the more water
it takes to bring it to field capacity. For example, clay soils that
are dry need much more moisture from irrigation before water
becomes available to plants. By the same token, these clay soils
take much longer to dry out, with the result that plants remain
turgid over a longer period of time.
Q.--What are the flatwoods soils of Florida?
These are the most abundant and familiar soils of Florida. They
occur on large flat areas in the state, supporting a native growth
of shrubs, palmettos, and pine trees. Flatwoods soils are very
acid, gray to black sands, and they have a low native fertility.
Forming the familiar ponds and swamps, the water table may be
just below the surface, at the surface, or above the surface of
the soil. With adequate drainage and other proper management,
many of these soils produce excellent crops and pastures.
Q.-Why does the black color of my garden soil disappear when
I dig down into it?
In many of Florida's sandy soils, a distinct leached zone appears
just below the surface. This is a natural condition which is
common to many soil types found in regions of high rainfall.
For similar soils that have not been plowed or cultivated, this
condition is even more pronounced.
Q.-What are some good summer cover crops for Florida gar-
For a moist soil, sesbania is one of the best. Soils that are well
drained will respond better to Florida beggarweed, hairy indigo,
Q.-Is all soil erosion bad?
Only the erosion that disturbs the balance of nature, or man-
made erosion that causes the loss of topsoil faster than it can
form, is detrimental. Natural erosion is a necessary factor in the
formation of world soils. We would have no soils if it were not
for the wearing down of the mountains and hills, the filling in
of the valleys, and the deposition of materials from streams, lakes,
Q.-What is the best way to prevent leaching of fertilizers?
Soils with a high colloidal content leach very slowly. Therefore,
humus, clay, or both are the principal inhibitors of fertilizer
leaching. Growing plants also prevent losses of fertilizers by
taking them up through the roots and returning them to the
tops. Growing plants and maintenance of organic matter are
the best protection against losses of fertilizers by leaching.
Q.-Why does my garden soil erode every time a heavy rain falls
I assume that your garden is on a slope and has some surface
runoff. The best way to stop erosion is to have plants growing
on a sloping garden the year around. The garden plants should
be set in rows across the slope, not uphill and downhill. If the
soil must be exposed to the elements for any length of time, it is
wise to leave a plant residue mulch on the surface to give some
protection from the beating rain and resulting runoff.
Q.-Will the use of fertilizer help in conserving the soil?
Fertilizers promote a heavy growth of all types of vegetation.
Soils that are low in fertilizer elements support little or no pro-
tective plant cover. These soils are subject to erosion. A good
cover of vegetation also promotes rapid infiltration of rains, due
to the undisturbed and unpacked condition of the soil surface.
Q.-What is the relation of plant residues and organic matter
to soil conservation?
Soils with a high organic matter content or with a liberal plant
residue on the surface, or both, allow for rapid infiltration of
rainfall and little or no loss of topsoil. Next to the growing
plant itself, plant residues and organic matter help retard soil
Q. -What is meant by infiltration of rain?
This pertains to the entrance of rain water into the soil. The
more porous and coarse the texture of the surface soil, the greater
the amount of infiltration of rain.
Q.-What is a simple method for constructing a small pond?
For shallow ponds of one acre or less, a simple earthen dam
with a suitable spillway can be constructed with ordinary farm
YOUR FLORIDA GARDEN SOILS
machinery. Generally, a double-disk plow and drag can be used
for making dams that need not be over 4 to 5 ft. in height.
For further information on farm ponds, contact your County
Agricultural Agent for free literature.
Q.-How can I prevent sand from blowing?
Plant fast-growing trees or shrubs that will yield height and
density. In general, the protection you gain from sand blowing
will be about ten times the height of the windbreak. A strip of
thick growing plants will retard soil blowing. For example, a
windbreak of pine trees is 40 ft. in height. You will get 400 ft.
of protection beyond the windbreak from sand blowing.
Q.-I have a small garden on sloping land. Should I put the
rows on the contour?
In a small garden, say 1/4 acre, it would be more practical simply
to run the rows across the slope, parallel to each other. For pre-
venting erosion in larger gardens, where the slope of the land
changes, it is necessary to use the contour system.
Q. -How can I conserve at least a part of the fertilizer that is
put on my garden?
There are several ways in which one may conserve at least a
part of the fertilizer. They may be listed as follows:
1. Use only split applications of fertilizer during the growing
2. Apply only the amount and kind that is recommended. Both
garden plants and cover crops of all kinds take up fertilizers
through the roots and return them to the tops. Residues from
these plants return fertilizers to the topsoil.
3. Do not overirrigate your garden. If the garden is on a
slope, prevent runoff at the surface by approved conservation
Q.-In preparation for planting lawn seed, I wish to plow and
harrow a steep slope this winter. Should I worry about the
Yes, you should. Because of its coarser texture, sandy soil will
allow much of the rain water to enter the soil. However, after
the soil profile is saturated with water, runoff can cause serious
erosion. See your County Agricultural Agent regarding a good
plan for the protection of sloping land.
Q.-I have an ideal site for a small pond. Is it worth while to
It is worth while to construct a small pond on your property.
Here are several good reasons for constructing one:
1. It keeps the water table of adjacent areas at higher levels.
2. It acts as a water storage for fire protection and irrigation.
3. It is excellent for watering livestock.
4. It makes an ideal recreational spot.
5. It adds to the resale value of your property.
Q.-What is soil puddling and how does this affect my garden?
When the surface of garden soil is exposed to a heavy rain storm,
it soon becomes sealed or puddled. The beating raindrops break
down the soil structure and fill in the voids with fine soil ma-
terial. This process soon seals the surface against infiltration of
rain water, allowing it to evaporate, or, in the case of slopes, to
cause surface runoff and loss of valuable topsoil.
Q.-Although my garden is flat land, I have been advised not to
leave it bare of vegetation. Is this correct?
In the conservation of soil and water, even on flat lands, plants
of any kind are helpful. Plant roots absorb and store valuable
fertilizers to be returned to the soil when the tops are turned
under. At the same time, they maintain the organic matter con-
tent of the soil. Growing plants keep soil porous, allowing water
to enter freely.
Q.-What is the best protection in preventing soil erosion?
Growing plants offer the best protection, the type determining
the degree. For example, a heavy grass sod is considered 100
per cent protection from soil erosion.
YOUR FLORIDA GARDEN SOILS
Q. -What part do roots of plants play in soil conservation?
They play a large part. Probably one-half of the soil organic
matter is maintained by the plant root residues of the soil. Plant
roots keep the soil porous, allowing rain water to enter readily.
Valuable fertilizer elements are returned to the tops of plants
where they augment fertility of the topsoil.
Q. -Why do I have more trouble with soil erosion in my corn
plot than in my sweet potato plot?
Corn is a clean-tilled crop that does not form a solid vegetative
cover for protecting the surface of the soil from beating rains.
Under these conditions, the surface of the soil soon puddles or
seals over, preventing the absorption of water. In sloping garden
soils, the accumulation of surface water could cause losses of soil
by runoff. Sweet potato vines form a compact cover of leaves,
which protects the structure of the soil surface from beating rains;
the raindrop force is broken and the water trickles into the un-
Q.-Is it true that soil can erode under a tree just as well as in
Soils will erode under trees. The degree of erosion depends on
the height of the lower branches from the ground and the amount
of ground cover under the tree. In grazed woods, where the soil
may be bare under a tree, it can be eroded easily. This is caused
by the extra large drops of water that fall from the branches of
the tree. If these large drops are intercepted by some form of
ground cover, the force of the droplets is broken. Without dis-
turbing the structure of the soil surface, water enters the soil
Q.-The rows in my garden run uphill and downhill. Why are
the plants at the bottom of the hill so much better than
plants at the top?
Whenever it rains, a portion of your topsoil and fertilizers is
moved down the hill. Finally, it concentrates at the base. Plants
growing at the bottom have the double benefit of their own soil
fertility plus that from the top of the hill. The solution to this
problem is to place the rows of plants across the slope rather
than uphill and downhill.
Q.-Do trees make good windbreaks?
Evergreen trees, that keep their foliage the year around, make
the best windbreaks. Of these, the fast-growing conifers are
Q.-Why are the erect types of plants in a garden less effective
in preventing soil erosion than the low spreading types?
In the erect type of planting, more soil is exposed to the beating
raindrops. Thus, more soil erosion takes place.
Q.-Is it good soil conservation practice to mix grass seed with
a selected legume prior to planting?
Many legumes are well adapted to Florida soils and definitely
improve growth of the grass and fertility of the soil they are
Q.-What is the best way to prevent leaching losses of fertilizers?
Keeping a growing crop on the land throughout the year is the
best way to prevent leaching losses of fertilizer.
Q. -I have heard that trees are good for protecting soils against
erosion, yet I have soil erosion under my trees. What is
If trees have something growing under them, they are good for
soil protection. Under a tree, drops of water falling to the
ground are many times larger than those falling from the clouds.
These large drops of water can do much damage to a bare sloping
soil under a tree. Grasses or shrubs growing under trees give
excellent protection against soil erosion.
Q. -Does Florida have a problem of wind erosion?
Yes, indeed. During the months of March, April, and May,
when prolonged dry spells are common, the newly-plowed sandy
SOIL AND WATER LOSSES
soils are exposed to the force of wind. This occurs where there
are few or no natural windbreaks, such as trees or buildings.
Winds of average velocity can remove smaller and lighter portions
of surface soil; winds of high velocity can remove coarse sand
Q.-How can wind erosion damage a garden plot?
Wind erosion attacks the surface soil which is the plow layer or
portion where plants find ideal growing conditions. The best part
of the plow layer is the organic matter, silt, and clay particles.
It is these small, light particles that wind picks up and carries off,
leaving coarse, sterile sand particles behind.
Q.-What part does soil texture play in the control of accelerated
Soil texture plays an important part in the control of accelerated
erosion. The coarser the texture, the more rapid the infiltration
of all types of rainfall, both heavy and light. In soils of coarser
texture, the moisture is stored in the soil and not left on the
surface to cause accelerated soil erosion. The opposite is true for
fine-textured soils such as clays.
Q.-What is meant by accelerated soil erosion?
Natural erosion is necessary for normal soil formation. When
this natural balance is disturbed, accelerated soil erosion takes
place, resulting in losses of soil and water.
Q.-I am told that the natural water table will drop if the land
is kept bare of growing plants. Is this true?
This is a true statement. Under the impact of rain, fallow soil
soon seals. Instead of entering the soil for natural storage, the
surface water evaporates or runs off the surface.
Q.-My garden soil erodes rapidly with a heavy rain and not
at all with a light rainfall. Why is this?
Even the most erodible soil will absorb and store moisture from
a light gentle rain. Because of its fine texture, this same soil
YOUR FLORIDA GARDEN SOILS
cannot absorb a heavy rainfall fast enough. Thus, much of the
rain water must remain on or flow off the surface.
Q.-What are some ways in which growing plants aid in soil
Growing plants aid in soil conservation in a number of ways.
1. Close growing plants form a protective shield against the im-
pact of rainfall.
2. Roots penetrate into the soil, allowing water to sink deeper.
3. Roots knit and bind the soil together, helping to keep it in
4. Dead roots add to the valuable organic matter in the soil.
5. Soil remains porous under plant growth, absorbing large
amounts of water.
Q.-Why are shallow surface soils more seriously damaged by
runoff or rain water than deep soils?
The depth in which weathered clay materials are found in a soil
designates whether it is deep or shallow. When the surface soil
is shallow, it has a limited ability for absorbing enough water
before it is saturated and runoff begins. The ability to absorb
rain water will also be influenced by the kind and intensity of
the rain striking the soil.
Q.-I am told to plant a legume for a cover crop. Why is this?
There are several good reasons why one should plant a legume
for a cover or green manure crop.
1. Legumes have nodules on their roots that contain symbiotic
bacteria which enable them to add nitrogen to the soil.
2. Legumes have a high content of proteins and lignins which
aid in the maintenance of the soil organic matter when turned
3. Selected legumes yield an abundance of foliage which aids in
protecting the surface of the soil against erosion.
4. Most legumes have a deep root system which enables them to
bring valuable plant food elements to the surface of the soil.
X THREE X
Fertility, Management, and Plant Growth
Q. -How can I arrange a good garden soil management calendar?
Go to your County Agricultural Agent's office and procure enough
vegetable production guides for the different plants you wish to
grow. Study these guides and fit the pertinent information to
your soil and climatic conditions. From this information, write
your garden soil management calendar. Be sure to note the sug-
gestions on fertilizer, moisture, pest control, soil reaction, and
Q.-What is a desirable ratio of sand, silt, clay, and organic
matter for a garden soil?
Garden soils come as they are. It is a matter of selecting the
best soil type available on your land. For general information,
a loam texture contains about 15 per cent clay, 40 per cent silt,
and 45 per cent sand. To make it an ideal garden loam, about
4 per cent of this mixture should be organic matter.
Q.-If I plant rye grass in the summer, will it compete with my
permanent lawn grass for moisture and nutrients?
Yes, it will. However, this should not prevent you from planting
rye grass. Make certain that your rye grass is kept moist and
well fertilized. By doing this, you will be taking care of both
the rye grass and live roots of your permanent lawn grass.
Q.-In some of my garden sprays, I use copper, zinc, and man-
ganese. Will these elements enter the soil, and will the
soil derive any benefit from them?
Some of the spray residue will drip from the leaves and branches
to enter the soil. In some instances, the amount that enters
the soil may be just as beneficial as the amount that can enter
through the leaves. After all, roots are designed by nature to be
highly effective in absorbing the necessary plant food require-
ments for the growing plant. The principal reasons for nutrient
sprays are to obtain a quicker response to certain essential plant
Q. -How can I use the leaf-drip area of my shrubs as a guide
for applying mixed fertilizer?
The leaf-drip area is the zone of the feeding roots of the plant.
This area is also far enough away from the trunk of the plant to
prevent burning by the raw fertilizer. When applying fertilizer,
this area is generally a safe distance for most plants.
Q.-Should fertilizer be applied when vegetables are setting
Generally, most vegetables have utilized all the soil nutrients
they need at this period of life. There are, however, some specific
instances in which a side-dressing of certain fertilizers may be
beneficial while the plants are setting fruit. For example, in order
to develop a firmer tomato, either potassium chloride or potassium
nitrate can be applied. At this period in the plant's life, such an
application will be utilized to develop thick walls in the fruit.
Q.-Are all of the plant food elements in the soil available to
Only a small fraction of the total amount of any essential plant
YOUR FLORIDA GARDEN SOILS
nutrient is available at any one time. The amount of nutrients
available depend on the type of plant, kind of nutrient, weather
conditions, type of soil, and moisture conditions within the soil.
For example: A loamy soil with over 40,000 lbs. per acre of
total potassium may yield only 200 lbs. per acre of available
potassium. Even this would be considered good under typical
conditions for most plants.
Q.-Why is cottonseed meal sometimes recommended for top-
dressing a growing lawn?
Cottonseed meal has a protein value of about 20 per cent, which
is considered relatively high. It is comparatively inexpensive.
When used as a top-dressing, it decomposes slowly, liberating a
steady flow of ammonia nitrogen into the soil. Some of the am-
monia is used directly by plant roots; much of it is oxidized into
nitrate nitrogen which is readily used by all plants. The higher
the protein content of the cottonseed meal, the higher the amount
of reserve nitrogen for future plant use.
Q. -The recommendation for my dooryard citrus calls for spread-
ing the fertilizer on the ground in the area of the leaf-drip.
What does this mean?
The leaf-drip is the area of the soil directly under the outside
edge of the crown of the tree. This area is assumed to be the
area of the feeding roots of the tree. The citrus tree receives
the plant food elements as they are washed into the soil by rains
Q.-I use high nitrogen fertilizer for my ornamentals to promote
blooms. Instead, I get a large amount of leaf growth. What
Nitrogen is the plant food element that promotes vegetative
growth. High nitrogen fertilizers, or any fertilizer that is supple-
mented with excessive treatments of nitrogen top-dressings, will
produce much leaf growth and less blooms. Nitrogen that is
balanced with phosphorus and potassium, in amounts that are
recommended for the kind of ornamental, will produce normal
growth and adequate blooms.
Q.-Can too much fertilizer be used on plants?
You can kill plants with too much or too little fertilizer. For the
plant and soil in question, it is good practice to stay as closely as
possible to the fertilizer recommendation. To believe that "if a
little is good, a lot is better" is a fallacy.
Q.-What is the nitrogen cycle?
The entire supply of nitrogen for native growth must come from
the atmosphere. This is accomplished by soil bacteria, rainfall,
and lightning. The largest amount of nitrogen is captured by the
soil bacteria and finally stored in the humus content of the soil.
As plants use some of the available nitrogen, they also contribute
to the humus content of the soil. Some of the nitrogen is reduced
to the atmospheric form to complete the nitrogen cycle of nature.
Q.-I always plant by the moon. This year the moon failed me.
What went wrong?
May I suggest that you disregard the moon and write the State
Agricultural Extension Service for a list of available bulletins
which supply scientific information on the culture of plants. This
Service has excellent publications covering all phases of garden-
ing. These bulletins cost the people of this country millions of
dollars and contain the most scientific information available.
They are free for the asking.
Q.-What are some good cover crops for garden plots?
Whenever possible, a good selected legume that fits the season
of the year should be selected as a garden cover crop. For in-
formation on the best legume for your area and soil conditions,
write to the State Agricultural Extension Service. Nonlegumes
such as oats and rye, or just weed growth, are better than leaving
soil exposed to the elements for any period of time. A good cover
crop not only protects the surface of the soil but also can be
YOUR FLORIDA GARDEN SOILS
turned under and used as a green manure crop to maintain the
organic matter content.
Q.-For better growth, should I keep the soil around plants
When a mulch is not used around plants, the surface soil tends
to seal over after a heavy rain, preventing good soil aeration.
Stirring the soil around the plant not only gets rid of weed com-
petition but also allows air to penetrate down to the feeder roots.
Q.-Can heavy soils be made more workable?
The most practical way to make Florida garden soils more work-
able is to turn under a heavy green manure crop well ahead of
planting. The green manure crop should be preferably a selected
legume. Both the roots and the decaying plant residues tend to
improve the structure of a fine-textured soil.
Q.-Do plants have different requirements for the different plant
Yes, they do. High nitrogen plants, such as corn, require several
applications of available nitrogen to mature properly. Tuberous
and root crops require a higher relative balance of potassium to
mature. Plants that do not have adequate amounts of phosphorus
do not set a normal amount of blooms and fruit. For practical
purposes, it is not possible to list the needs for every plant known.
Instead, these plants are grouped according to their fertilizer
needs and treated accordingly.
Q.-How would I proceed to make a selected virgin soil into
good garden soil?
When converting virgin soils into garden soils, the following
definite steps may be taken:
1. The site should afford ample light for favorable plant growth.
2. Plan for adequate moisture control for the garden.
3. Test for soil reaction and apply lime as needed.
4. Keep the soil in a well-aerated condition by proper plowing
YOUR FLORIDA GARDEN SOILS
5. Stick to a recommended program of fertilization and top-
6. Maintain a recommended program of pest control.
7. Keep down competing weeds.
8. Maintain the organic matter by growing a selected cover crop
during off seasons.
Q.-What kind of soil do I need for growing azaleas?
Any well-drained acid soil with a fair amount of organic matter
will grow good azaleas. Because of the shallow root system, it
is important to keep a heavy mulch of leaves around the plants
at all times. Try to avoid sweet soils by not planting azaleas with
plants that require sweet soil. Azaleas do best in soils with a pH
of 5 or less.
Q.-Do some fertilizers tend to change the pH of the soil? If
so, can I use them to help adjust the soil pH?
Some fertilizers do help change the soil reaction. By regular
application of certain fertilizers, it is possible to alter and main-
tain some change in soil pH. For example, top-dressings of am-
monium sulfate will tend to make the soil more acid. Yellow
sulfur mixed with fertilizers will definitely alter the soil pH to
a more acid value.
Q.-What are some advantages and disadvantages of foliar
The advantages of foliar feeding with the major plant food ele-
ments are doubtful. However, the advantages of foliar feeding
with minor elements are well known. Foliar feeding has the
advantages of quickly correcting a minor-element deficiency in a
plant with a minimum amount of effort and cost. On the other
hand, the corrected deficiency is not permanent and must be
repeated unless the conditions are corrected in the soil.
Q.-I am told to use more fertilizer in smaller amounts and
more frequently on sandy soils. Why is this necessary?
To prevent losses by leaching. In humid regions, fertilizers can
be readily leached from coarse sandy soils. Plants can use only
small amounts of fertilizer at a time. An excess can be harmful
to the plant and is also subject to leaching.
Q.-Should I use all the fertilizer I plan to at planting time?
This depends on the climate and the soil. For northern climates
with less rainfall and heavy soils, this practice is recommended.
For Florida conditions of heavy rains and sandy soils, it is unwise
to put the basic fertilizer recommendation down at planting time.
To assure a constant flow of nutrient elements for plant growth,
the initial application of fertilizer is generally split into two or
Q.-Where can I obtain good information on growing vegetables
There are no better sources of information on vegetable growing
in Florida than the Florida Vegetable Production Guides. Com-
plete within themselves, these circulars cover most of the im-
portant vegetables grown in this state. They are available, free
of charge, from the Agricultural Extension Service, University
of Florida, Gainesville, Florida.
Q.-The peanuts growing in my garden are all pops. What is
Peanuts, like other legumes, have a higher demand for available
sulfur and calcium than many other kinds of plants. If suffici-
ent amounts of available sulfur and calcium are not present when
peanuts begin to peg down, pops will result. They can be pre-
vented by applying from 1 to 2 lbs. of gypsum (calcium sulfate)
per 100 sq. ft. of garden area when the peanuts begin to peg
Q.-What is meant by washing in a fertilizer?
This term is used to describe a process for preventing tip burn
and root damage when raw fertilizer is applied directly on grow-
ing plants. For example, after spreading fertilizer on a green
YOUR FLORIDA GARDEN SOILS
lawn, the fertilizer should be washed into the soil. In this way,
it is diluted and becomes available immediately to the growing
Q.-Which does a plant utilize the best: a spray of minor plant
food elements or a spray of major plant food elements?
Plants respond readily to a spray of minor elements and make
little response to a spray of major elements. The reason is that
plants require only minute amounts of minor elements which
they absorb through the pores of the leaves and stems.
Q.-What is the relation between a green manure cover crop
and the amount of fertilizer to use?
This depends on the kind of green manure crop, prior soil treat-
ment, and how much of the cover crop is turned under. When
turned under, all green manure crops add some nitrogen, phos-
phorus, and potassium to the soil. If they were well fertilized,
they would add a great deal more. If they were a selected legume
and fertilized accordingly, they would save the cost of nitrogen
fertilizer and add some phosphorus and potassium. In any case,
the amount of additional mixed fertilizer applied should be esti-
Q.-Is superphosphate good for trees?
Superphosphate is a carrier of phosphorus and calcium which
are both essential plant food elements. Trees, like other plants,
have need for all the essential elements in certain quantities.
Trees growing in acid or sweet soils would probably respond to
applications of superphosphate. Under most conditions, trees
make greater response to applications of nitrogen and potassium.
Q.-Are organic forms of nitrogen important in Florida sandy
Organic forms of nitrogen have their place in the soil manage-
ment program for Florida sandy soils. This, of course, depends
on the degree of organic matter content of the soil in question.
Some sandy soils of Florida are quite high in organic matter and
low in clay content. In this case, the organic forms of nitrogen
may not be as useful as inorganic forms. For sandy soils that are
low in organic matter, the addition of organic forms to the mixed
fertilizer may be quite beneficial, especially for specific plants.
Q.-After I apply nitrate of soda top-dressing, how can I prevent
my lawn from turning brown?
No burning of the grass blades will result if the recommended
amount of nitrate of soda top-dressing is washed immediately into
the soil with the garden hose. Tip burn is due to the high con-
centration of salt directly on the grass blades. Watering dilutes
the salt and washes it into the soil where it will do the most good.
Q.-Does the kind of fertilizer I use cause my tomatoes to wilt?
Not directly. During the warm growing season, high amounts of
readily available nitrogen can easily cause a succulent soft growth,
thus making the tomato plant susceptible to attack by wilt dis-
eases. With a balance of higher potassium and lower nitrogen,
tomato plants develop a firmer, drier growth, which is more
resistant to wilt attacks.
Q.-Can I put mixed fertilizer and seed in the same row?
This method will quickly kill the germinating life in the seed.
The high concentration of the salt solution around the seed draws
out the moisture needed for germination.
Q.-How does chelated iron work in the soil?
Chelated iron is a special organic compound that has the ability
to bond a source of available iron just strong enough to resist
fixation, and weak enough to liberate a steady flow of available
iron for plant growth. Other forms of iron from soluble salt
sources are difficult to keep in available condition over relatively
long periods of time. The free iron from these salts is quickly
fixed, or made insoluble, in the soil solution. When in contact
with other elements, iron has a strong tendency to form many
insoluble salts, as well as being rather strongly adsorbed by the
colloidal content of the soil.
........... IS A REAL PLANT STARTER
.:. :- :: *'.. ". .. -.- .' .- ,. -, .': .'K. o. - . . o'.
.'.;*'.-."*' .:. '* :: :. .-. .'. '.'. --. ',.'- ..:: *, .l..-.
Q.-Should the shrubs around my house be fertilized more than
once each year?
On the majority of soil types, two times a year for most plants
should be sufficient. The first application of a complete mixed
fertilizer may be applied late in the winter so that the roots will
begin to develop first. Later, as the weather becomes warmer
and the rains begin, the tops will make rapid growth to balance
the root growth. During the height of the rainy season in mid-
summer, much of the readily available plant food is leached from
the soil faster than the plants can absorb it. At this time, it is
advisable to apply a light top-dressing of available nitrogen.
Q.-What is meant by native soil fertility?
This means the soil fertility level of any area before it was dis-
turbed by man. The physical and chemical characteristics of
native soils remain in equilibrium with their local environment.
Q.-To prevent injury, how far away from the seed should fer-
tilizer be banded?
The fertilizer should be placed in bands from 2 to 3 in. deep
and 2 to 3 in. on either side of the seed.
Q.-Would a broadcast top-dressing of superphosphate be as
efficient as a nitrate of soda broadcast?
When placed in bands or mixed with the soil, superphosphate is
much more efficient. This is true because the available phosphate
in this fertilizer remains wherever it is placed in the soil. Quite
the opposite is true for nitrate of soda, which is highly soluble.
The available nitrogen migrates rapidly in the soil solution,
thereby making nitrate more efficient for broadcasting.
Q.-What plant nutrients tend to cause a plant to mature late
High amounts of potassium and nitrogen, in relation to other
plant nutrients, tend to cause a plant to mature late in life.
Q.-What special effect does sulfur have on plant growth?
Without the element sulfur, plants will not grow normally. Sul-
36 YOUR FLORIDA GARDEN SOILS
fur is a part of the plant protein which is essential for cell devel-
opment. Sulfur is also found in several plant oils. Chlorosis, or
yellowing of the leaves, takes place when sulfur is deficient in
Q.-What is the best way for preventing loss by leaching of the
fertilizer applied to soil?
Losses of fertilizer by leaching may be greatly reduced by apply-
ing split applications of the regular recommendation. For ex-
ample, a recommendation calling for 400 lbs. of fertilizer per
acre on a soil that is excessively drained may be split into two
parts. Depending on local conditions, the first part should be
applied as recommended and the last half applied sometime later.
On extreme drought soils, it may be an advantage to divide the
fertilizer recommendation into three parts.
Q.-What special effect does phosphorus have on plant growth?
Phosphorus is part of the tissue which has to do with the repro-
duction of the cell. Phosphorus promotes healthy root growth,
seed formation, and plant oil formation. During the growing
period of the plant, good flowering and fruiting depend on having
a good supply of available phosphorus in the soil.
Q.-How would you maintain a good soil for gardening?
When maintaining a garden soil, the following factors should be
1. Organic matter: Keep the organic matter content of the soil
as high as possible by turning under sufficient plant residues
and cover crops.
2. Soil fertility: Supply the soil with enough of the right kind
of fertilizers. Supply lime when needed.
3. Soil diseases: Rotate the garden plot if possible to help keep
down soil-borne diseases.
4. Soil moisture: Supply adequate moisture when needed.
Q.-What special effect does calcium have on plant growth?
Within the plant, calcium is found as both organic and inorganic
salts. Calcium is active in connection with the reproduction of
new cells as shown by the death of the terminal bud and the
twisting of new growth when it is deficient. Ample amounts of
calcium in the soil promote healthy green growth and, particu-
larly, healthy white root development. Plants with the proper
amounts of this element show a definite resistance to disease.
Q.-What special effect does nitrogen have on plant growth?
For obvious reasons, this is the element most often deficient in
both plants and soils. Nitrogen, important in the formation of
plant proteins, also promotes a vigorous green growth in plants.
Conversely, too much nitrogen can promote growth that is soft
and subject to cold and disease damage. Too little nitrogen
causes yellowing of the leaves of the plant.
Q.-Can some plants get too much ammonium nitrogen and not
enough nitrate nitrogen?
This is true for certain plants. As an illustration, such plants
as rice mature with only ammonium nitrogen as a nitrogen
source. The potato is another example. Potatoes do well with
rather high amounts of ammonium nitrogen in the soil. How-
ever, higher levels will cause leaf curl and yield drops. Most
other plants will tolerate ammonium nitrogen up to a certain
level. Above this level, it becomes toxic.
Q.-Are sandy soils improved by the addition of organic ma-
It is most important to maintain as much organic matter content
in sandy soils as possible. Any kind of plant residues should be
turned under well ahead of planting. Green manure crops, such
as hairy indigo or lupines, may be grown between the growing
seasons and turned under a month or so before planting. There
is an old saying that "organic matter is the fat of the land," which
is certainly true for sandy garden soils.
Q.-What special effect does magnesium have on plant growth?
Magnesium is the only mineral element that is actually part of
APPLY 2 POUNDS OF AN 8-8-8 MIXED FERTILIZER
FOR EACH INCH IN DIAMETER OF THE TREE TRUNK
AT WAIST HEIGHT.
DISTRIBUTE THIS AMOUNT IN THE HOLES ILLUSTRATED.
FERTILIZING A SHADE TREE
the chlorophyll molecule in plants. Without magnesium, the
sugar-making chlorophyll cannot function; magnesium deficiency
will soon appear in the leaves. Thus, magnesium promotes
healthy green growth in plants.
Q.-Does the ammonium nitrogen of the soil have a different
effect on plants than nitrate nitrogen?
The amount of ammonium nitrogen that plants can use is largely
dependent on the kind of plant. In any case, the ammonia ion
is used directly by the plants in manufacturing amino acids.
Thus, it is not stored in any quantity in the conducting tissues
as nitrate nitrogen. Excessive amounts of ammonium nitrogen
tend to cause most plants to put on a rapid soft green growth.
Q.-What is a satisfactory method for fertilizing shade trees?
When shade trees are fertilized, it must be done in such a way
to eliminate competition with lawn grass or other plants. The
fertilizer must be placed deep enough for tree roots to make use
of it. First punch holes around the tree at about the leaf-drip,
these holes being about 24 in. apart and approximately 18 in.
deep. Distribute 2 lbs. of an 8-8-8 mixed fertilizer for each inch
in diameter of tree trunk at waist height in all of the holes. For
example: A 10-in. tree would require 20 lbs. of mixed fertilizer
to distribute among the punched holes.
Q.-I have been told to use a regular vegetable fertilizer for all
plant needs. Is this good practice?
Such advice will never be heeded by the intelligent or trained
gardener. Too many growth failures of plants are due to the use
of the wrong kind of fertilizer. Besides a dozen or more definite
ratios of blending nitrogen-phosphorus-potassium, there are also
acid-forming fertilizers, organic fertilizers, soluble fertilizers, and
many other combinations. Your State Extension Service guides
will recommend the proper fertilizer for garden plants. It is good
practice to follow this information carefully.
Q.-What per cent organic material should I have in my garden
40 YOUR FLORIDA GARDEN SOILS
Organic material in mixed fertilizers is beneficial when used on
sandy soils low in humus. On soils that have a medium to high
amount of humus content as well as good cover growth, it would
be unrealistic and expensive to purchase mixed fertilizers high
in organic material.
Q.-What forms of nitrogen do plants get from the soil solution?
From the soil solution, plants absorb both ammonium nitrogen
and nitrate nitrogen. In sweet soils, ammonium nitrogen is
quickly oxidized by soil bacteria into nitrate nitrogen during the
Q. -What steps should I take when preparing my soil for a
Remove all foreign materials, such as bricks, mortar, scraps, and
other debris. Disk the soil and level the surface to prevent any
depressions. For sandy soils with low fertility, spread 1 in. of
peat or muck over the area. If this material is very acid, spread
3 to 5 lbs. of finely ground dolomitic limestone per 100 sq. ft.
At the last leveling operation, work 2 to 5 lbs. of a complete
8-8-8 fertilizer into the topsoil per 100 sq. ft.
Q.-What are some good soil management practices for day-
Around the clumps of daylilies work into the soil a complete
fertilizer, such as 6-6-6 or 8-8-8. Do this in early January.
Then fertilize again after blooming to assure profuse flowering
the next year.
Q.-What is the best way to manage flower beds in landscape
The soil should be hoed, smoothed evenly, and covered with a
heavy mulch of leaves to keep down competing weeds. Constant
edging is necessary to prevent the lawn grass from creeping into
the plant beds.
Q.-Is it true that azaleas grow best under a heavy mulch of
Azaleas require a heavy mulch for good growth. The root system
of azaleas is shallow; when not covered with a heavy mulch,
roots soon dry out, causing the azaleas to wilt. A good mulch
around azalea plants also contributes toward more uniform soil
temperature, nutrient supply, and superior maintenance of soil
Q. -I don't seem to have a green thumb. What are a few steps
that I can take to improve plant growth?
Consider the principal factors for plant growth and provide these
needs as much as possible. Plants must have proper amounts of
air, light, moisture, nutrients, and protection from pests. These
requirements call for a soil with good texture, structure, organic
matter content, and adequate plant nutrients to support thrifty
plant growth. Optimum soil moisture conditions must be main-
tained from irrigation, natural rainfall, or both. The plant should
be located to fit its light and temperature requirements. Com-
peting weed growth should be removed.
Q.-When is the best time to cultivate my garden?
Your garden should be cultivated before the lateral feeding roots
have extended too far into the row. Early cultivation stirs the
soil and allows the air to reach the fast-growing roots. If the
garden is cultivated after the plants have grown too large, there
is a possibility of cutting these roots and damaging the growth
of the plant.
Q.-I would like to have some easy-to-read and simple informa-
tion on growing Florida vegetables. Is such information
available and where can I get it?
The Florida Agricultural Extension Service has some excellent
pamphlets called production guides. You can obtain them at any
County Agricultural Agent's Office.
Q.-I have been advised to spade my garden shallow to prevent
mixing the topsoil with the subsoil. Is this the best practice?
If your garden is made up of black sands, the shallow spading
YOUR FLORIDA GARDEN SOILS
seems to be the best method, since you get more use from the
soil organic matter content. If your garden is low in organic
matter and has a thick sandy surface over clay subsoil, then deep
spading of your garden will tend to mix the clay with the sandy
topsoil and improve the moisture-holding capacity of the soil.
Q.-We are trying, with little success, to establish azaleas near
our house. What is wrong?
Nine times out of ten, the trouble is due to the accumulation of
lime and mortar material left there after the home was con-
structed. Have the soil tested for acidity by your County Agri-
culttural Agent. If the pH of the soil is 6 or more, it should be
made more acid by using a heavy acid peat mulch and a chemical
supplement such as aluminum sulfate, yellow sulfur, or iron
sulfate. Of the three chemicals, yellow agricultural sulfur is
the safest and lasts the longest. Carefully apply according to
Q.-Why do plants seem to grow better if the soil is not too
This depends on the soil texture. It would be difficult to pack
a coarse-textured soil to such a degree that air and roots could
not enter freely. Fine-textured soils can be packed to the extent
that plant roots have difficulty penetrating the soil as well as
having sufficient air for respiration.
Q.-What are several good methods for controlling weeds?
Most weed eradications are based on the following principles:
shading them out, starving them out, or killing them by chemical
means. Weeds can be shaded out by using a suitable heavy
mulch around the plants. Weeds can be starved out when it
is possible to fertilize the cultivated plant and not the weeds.
Modern weed-killing chemicals can be used to control weed
growth if the chemical is carefully selected and the directions
followed to the letter. However, the old-fashioned method of
pulling weeds is still commonly used.
Q. -My plants make good growth but produce little or no vege-
tables. What is the trouble?
The two principal causes of excessive vegetative growth with lack
of fruiting are limited exposure to light, and too high a level of
available nitrogen. The plant can be affected by either one or
a combination of these two causes.
Q.-Why do some plants volunteer better each year on some
soils than on others?
Generally speaking, the more fertile soils tend to support more
plant growth, which contributes toward more soil organic matter.
Plants that seed on these soils find the temperature, mcnture,
and nutrient supply more nearly ideal for seed germination and
consequent volunteer growth. On very sandy soils, the lack of
protection of the seeds, high temperatures in the summer, and
lack of moisture tend to prevent volunteer growth.
Q. -When too much fertilizer is used, what are the plant symp-
In overfertilized plants, the first revealing symptoms are scorched
tips of foliage, often termed tip burn. If the symptoms persist,
the leaves will dry up and fall to the ground. Plants in this
condition should be soaked with water to help leach out some
of the soluble salts in the soil.
Q.-If 6 oz. of chelated iron is recommended for a camellia
bush, would 1 lb. be better?
This is a sure way to kill the camellia bush. In small recom-
mended amounts, chelated iron is efficient in liberating enough
iron into the soil for plant use. When compared with most fer-
tilizing compounds, the nature of chelated materials makes it
long-lasting. If too great a quantity of these chelated materials
is applied, the long-lasting effects will not only kill the plants,
but will remain in the soil to damage future plant growth.
Q.-How often should a complete fertilizer be applied to my
YOUR FLORIDA GARDEN SOILS
If your garden soil is sandy, it is wise to use a split application by
applying one half at planting and the remainder about the middle
of the growing season. Additional nitrogen may be supplied dur-
ing the season by 2 or 3 light applications of available nitrogen
in the form of nitrate of soda or sulfate of ammonia.
Q.-Is it necessary to wash chemical fertilizers into the soil?
Wherever there is a possibility that either the tops or roots may
be injured by raw fertilizer, it is wise to wash the fertilizer into
the soil. Examples are, lawn grass or azalea beds.
Q.-What is a satisfactory method for placing mixed fertilizer
Sprinkling the recommended amount around the shrub at the
leaf-drip is one of the most practical methods for applying ferti-
lizer. This is the outer edge of the foliage on the shrub.
Q.-At what time of the year should shade trees be fertilized?
Trees may be fertilized at any time of the year. However, since the
utilization of available plant food nutrients in the soil is greater
during the spring and summer months, it is preferable to fertilize
during these seasons. This is especially true of deciduous trees
which remain dormant during winter months.
Q.-Why do successful vegetable gardeners apply fertilizer in
bands rather than broadcasting it?
There are several reasons why gardeners apply fertilizers in
bands. It takes much less fertilizer for the garden, the plants
make better and more uniform growth, the fertilizer will not burn
the plant or prevent germination of seeds, band fertilization pro-
motes root growth, and more efficient use is made of the phos-
phorus content of the mixed fertilizer.
Q.-Can plants absorb nutrients as fast and in the same quantity
through their foliage as they do through the root system?
When compared with the foliage portion of the plant, the roots
of the plants have been designed by nature to absorb large quan-
MAKING A SEED FURROW AND COVERING FERTILIZER
IN ONE OPERATION
YOUR FLORIDA GARDEN SOILS
titles of soil nutrients at more efficient rates. Foliage can, how-
ever, absorb enough of the minor elements to correct deficiencies
when they occur. The advantage of minor-element sprays for
plants is in the speed that is achieved for correcting deficiencies.
Since the minor elements are not translocated from one part of
the plant to another, this is possible.
Q.-What is a recommended amount of mixed fertilizer to apply
to a garden?
For most soils, 3 or 4 lbs. of mixed fertilizer are applied to 100
sq. ft. of garden surface. Refer to a garden bulletin for amounts
and methods of application best suited to local conditions.
Q.-What is best for gardens: farm manure or commercial fer-
Use both by balancing farm manure with a 4-12-12 commercial
fertilizer. If farm manure is fresh, it should be worked into the
soil well in advance of planting. Follow by applying the recom-
mended amount of 4-12-12 fertilizer. The farm manure should
contribute the remaining portion of nitrogen necessary for good
Q.-Is it worth while to fertilize annuals?
For most sandy soils of Florida, it is well worth the effort to
fertilize annuals. However, this depends on the kind of annual
you wish to grow. If you wish to grow large vigorous plants,
additional fertilizer is necessary on most soils. Depending on the
variety of plant, some annuals will require more or less fertilizer.
Q.-How does the plant make use of nitrogen applied to the
Nitrogen is one of the building blocks in the manufacture of
proteins by plants. This fact is highly important to the plant,
especially to those plants used as foods.
Q.-In addition to manure and compost, why is it necessary to
add a complete fertilizer to a garden in order to set more
Since both manure and compost are too low in phosphorus to set
a satisfactory amount of fruit, they are not complete fertilizers.
Plants will generally show good response to potassium as well.
A supplemental amount of a 4-12-12 commercial fertilizer on
this garden should grow satisfactory crops.
Q. -How should fertilizer be applied to a planter box?
Fertilizer may be applied either in dry form or in solution. If it
is applied in dry form, it is good practice to wash the fertilizer
into the soil with enough water to moisten it. For either method,
it is important to follow directions carefully in order to apply
the correct amounts of fertilizer.
Q.-I have been told by an organic gardener that chemical ferti-
lizers destroy bacteria and humus in the soil. Is this true?
Soil bacteria are plants and require mineral elements just as
plants do. Without these mineral elements, the soil bacteria
would not be able to decompose plant residues and produce soil
humus. Too much fertilizer of any kind will harm plants as well
as soil microbes; proper amounts applied correctly are highly
beneficial for both higher plants and soil microbes.
Q.-Will plants grow better if only organic fertilizer is used?
As long as they are in a weak water solution, plants have no
special preference as to the source of their nutrient elements.
The principal advantage for using organic fertilizers is in their
slow liberation of these nutrient elements for plant use. Plants
that are grown for high yields and size in the same soil, year after
year, must be supplemented with inorganic fertilizers. This is
especially true for the sandy soils of Florida.
Q.-Is it safe to use poultry manure on potted plants?
It is best not to use fresh poultry manure on potted plants. Prior
to using poultry manure on plants, it should go through a period
of decomposition. Decomposed poultry manure has no offensive
odor and will liberate more available nutrients for plant use. One
of the best ways to use poultry manure is to compost it with
leaves prior to use as a potting mixture, or apply directly on
plants after the period of decomposition.
Q.-Before planting a tree, why is it advisable to add some super-
phosphate in the bottom of the hole?
Because in many soils phosphorus is the one plant food element
often deficient. This element fixes readily with the soil and does
not move from place to place as does nitrogen. Therefore, a pound
or two of superphosphate, placed in the planting hole and mixed
well with the soil, should be beneficial in tree planting.
Q.-Do plants need an application of vitamins for best growth?
Since plants are the world's best suppliers of vitamins, they do not
need any additional for better plant growth. Plants manufacture
their own vitamins in great abundance.
Q.-Should I fertilize St. Augustine and centipede grasses at the
same time with the same fertilizer?
In both texture and growth habits, these two grasses are quite dif-
ferent. Centipede is an acid-demanding grass and St. Augustine
does better in sweet soil. St. Augustine grows much faster and
larger than centipede, thus using more fertilizer. Centipede is
known as a low-maintenance grass. It is possible to use the same
fertilizer, but the amount and frequency used for centipede should
be less often and in smaller amounts.
Q.-Is it safe to apply wood ashes to garden soil?
As a general rule, wood ashes are excellent for applying to garden
soil. They not only sweeten the soil, improving its physical prop-
erties, but also add some potassium, calcium, and magnesium.
On the other hand, wood ashes may be harmful in a garden loca-
tion where acid-loving plants are growing. In this case, the de-
creased acidity may tend to fix iron and manganese, causing leaf
Q.-How often should my lawn be fertilized?
The kind of lawn and the weather should dictate the fertilizer
needs. Centipede lawns require much less fertilizer than a St.
YouR FLORIDA GARDEN SOILS
Augustine lawn. During the rainy season, it may be necessary to
top-dress with available nitrogen several times in order to keep a
healthy green color. In general, most lawns require a spring and
fall application of a complete mixed fertilizer, with several top-
dressings of available nitrogen during the rainy months in sum-
Q.-I use a large quantity of citrus fertilizer. Can I use this fer-
tilizer on other plants?
In a citrus fertilizer the content of minor elements, especially
copper, prevents its wide use on other kinds of plants.
Q.-Is there any advantage in using a soluble 10-10-10 fertilizer
over a granular 10-10-10 fertilizer?
This depends on the use of the fertilizer. If the plants need a
starter solution, then the 10-10-10 soluble mixture is the correct
selection. When cost must be considered and heavy rains are fre-
quent, the granular 10-10-10 is a wise selection. Granular
10-10-10 is a high-analysis fertilizer with no filler; consequently,
the cost per pound of plant food is relatively reasonable. The hard,
uniform granules remain through several showers of rain and are
quite resistant to rapid leaching.
Q.-Why is there so much talk about getting the phosphate fer-
tilizer in the soil before and not after planting?
If time and other factors allow, this is an excellent way of keeping
a steady flow of available phosphorus for plant use. Since phos-
phorus is readily fixed by all soils, it does not move far from its
original position. Four or five times the actual amounts needed
by plants are generally applied to take care of soil fixation. By
mixing a liberal amount of superphosphate in the soil prior to
planting, the soil will adjust itself to the phosphorus supply, lib-
erating small amounts throughout the season for plant needs.
Q.-My neighbor is growing tomatoes in wood shavings. What is
she adding to make them grow?
She is adding a nutrient solution containing all 16 plant food
YOUR FLORIDA GARDEN SOILS
elements. These soluble salts may be purchased in balanced form
from your feed and seed store. They are added to a given quantity
of water and sprinkled on the wood shavings as required.
Q.-Is there a connection between fertilizing and bloom drop?
Yes, there is some connection. Overfertilization can be the greatest
cause of leaf and bloom drop. Other conditions that may cause
leaf and bloom drop are too high a content of potash or nitrogen,
cold damage, and certain soil-borne diseases.
Q.-How often should I fertilize?
A blanket answer cannot be given for this question. Allow the
kind of plant and the type of soil to be your guide for the time,
amount, and kind of fertilizer to use. A large amount of informa-
tion may be obtained by reading the many bulletins, production
guides, and pamphlets that are distributed, free of charge, by
your State Agricultural Experiment Station and Extension Service.
Q. -When is the best time to fertilize azaleas and camellias?
In the early spring and again during the summer rainy season.
The early application is for the purpose of root development. The
summer application is for the purpose of taking care of losses of
fertilizer by leaching, and for top growth.
Q.-Can nutrient elements be fed entirely through the leaves?
Recent research has shown that this is not possible. It is possible
to supply minor elements by foliar spray. It is impossible to supply
the entire needs of the plant for the major elements by foliar
Q.-Can a special fertilizer be used to change dogwood tree
blooms from white to pink?
Fertilizer has no relation to the color of dogwood tree blooms.
Q.-I applied the recommended amount of fertilizer and have
had 8 in. of rainfall. How much of the fertilizer should be
left in the soil?
If all the initial fertilizer recommendation was applied, some of
it will be lost by leaching. How much fertilizer and nutrients will
be lost will depend on several factors:
1. The soil type: The sandier the soil, the greater the loss.
2. The kind of nutrient: Phosphorus is the last to leach out.
3. If the garden was fallow or if vigorous growth was present.
4. If the rain was light over a long period of time, or heavy over
a short period of time.
Q.-Why doesn't native growth in the woods and fields turn yel-
low in color from lack of nitrogen fertilizer?
These plants have adapted themselves to the amount of nitrogen
in the soil they are growing in. Native plants that have a rel-
atively high need for nitrogen are found in areas where sufficient
nitrogen is present in the soil. When undisturbed by man, nature
tends to establish its own ecological balance.
Q.-What is soil fixation of plant food elements?
When any readily available plant food element in the soil is con-
verted to a form that plants are unable to utilize, this is known as
fixation. Fixed plant nutrients may not be available for the im-
mediate needs of plants, but they can be available after a period
of weathering or biological activity. In order to take care of fixa-
tion in the soil, phosphorus is often applied in a much larger
quantity than plants need.
Q.-What is meant by the terms leaching and percolation?
Percolation is the natural infiltration of rainfall down through
the soil profile. Percolation water enters the normal water table
of the soil where it is stored for future use. Leaching pertains to
the removal of soluble plant food elements by excessive amounts
of water within the soil profile. In many of our Florida sandy
soils, leaching is a special problem.
Q.-If I let my garden spot remain idle for several years, will it
become more fertile?
After mineral soils are taken out of production, they become less
fertile. The leaching rains remove the extra plant nutrients nec-
essary for intensive garden growth of vegetables. However, leach-
ing also lowers the population of harmful nematodes in a garden
soil. Native growth will begin to thrive, since some nitrogen enters
the fallow soil from rains, microbial activity, and decomposition.
Q.-Can I burn azaleas by putting too much iron sulfate too
close to the root system?
Azaleas can be burned by applying too much of any readily avail-
able fertilizer too near the roots. This is especially true of the
more soluble inorganic fertilizers. Since azalea roots are near the
surface, the plants are easily burned if the fertilizer is not applied
Q.-What is meant by building up a garden soil?
This term applies to treating a soil to obtain its top productivity.
This can be accomplished with special attention to the soil mois-
ture condition, soil structure, organic matter content, fertility,
and liming needs. See your County Agricultural Agent for bulle-
tins on this subject.
Q. -My garden soil is good and I use fertilizer, yet my corn
plants turn yellow when they reach a height of about 4 ft.
What is wrong?
Your fertilizer program is off balance. You probably used only the
initial application of mixed fertilizer and did not apply the avail-
able nitrogen side-dressing when the corn was knee-high. Without
this side-dressing on soils low in organic matter, corn will not
Q.-What causes the roots of my vegetables to rot?
It could be plant pests or waterlogged soil, probably the latter.
Roots of most vegetables will not live long in waterlogged soil.
Waterlogged soils cut off the supply of oxygen so vitally needed
by growing plants.
Q. -My yard is made up of dredged subsoil. Can it be used to
YoUR FLORIDA GARDEN SOILS
Yes, it can be used. You can either grow a good green manure
crop and turn it under at maturity, or work 2 or 3 in. of black
peat into the topsoil. The idea is to add some organic nitrogen to
the soil, as well as improve its structure.
Q.-Why do some soils require more fertilizer than others for
the thrifty growth of plants?
There are many types of soils. They vary as to nutrient supply,
moisture conditions, soil reaction, organic matter content, texture,
and structure. To support the growth of cultivated plants, the
coarser-textured soils with low organic matter content need addi-
tional supplies of fertilizer. Other finer-textured soils hold more
moisture against leaching, thus retaining more fertilizer for the
benefit of plant growth.
Q.-Is it a good idea to clean cultivate around the trees in my
If enough fertilizer and moisture are used for both the lawn and
the tree, it is not necessary to clean cultivate around your lawn
trees. If this is impossible, especially around fruit trees, then it is
a good idea.
Q.-Will soil alone cause a difference in the taste of vegetables?
If plants get all 16 essential elements in the right amounts and
proportions and have enough heat, light, and moisture, they will
taste the same in any medium supporting plant growth. Soils
alone will not make any difference in the taste of vegetables.
Q.-Although I planted my tomatoes in the shade and gave them
plenty of nitrogen fertilizer, they are all stem and leaf. What
did I do wrong?
You gave your own answer. You planted them in the shade with
plenty of nitrogen fertilizer. This is the best way to grow leaves
and vines. A balanced fertilizer should be used. Grow the toma-
toes in the open sun so the carbohydrate balance will be in favor
of blooms and fruit.
Q.-I have heard that soils contain colloidal material. If this is
true, of what importance are they?
Soils contain several different mineral colloids as well as organic
colloids. These colloidal materials are probably the most impor-
tant substance in a soil. One cu. ft. of clay soil may have 2,000,-
000 sq. ft. of surface area, all of which is exposed to moisture,
chemical reactions, and biological activity. The more one knows
about the colloidal content of a soil, the better understanding he
will have of its relation to plant growth.
Q.-In planning the location of a garden, should one take into
consideration the soil type, location of trees, buildings, and
slope of the land?
Yes, indeed. A soil with good moisture conditions and a favorable
amount of organic matter should be selected. If grown under too
much shade, plants tend to become vegetative. If some shade is
necessary for certain types of plants, it should be in the late after-
noon and not in the morning. Most garden plants do best in the
Q. -Is it necessary to fertilize black soils?
In black soils of Florida, the only element that may be present in
relatively high amounts is nitrogen. Until the soil is properly
managed, this nitrogen is mostly unavailable. Potassium, which
is used in large amounts by growing plants, is actually deficient
in black soils, such as mucks. Just as the mineral soils of Florida
need good soil management, so do the black soils.
Q.-Why do plants need such small amounts of the minor or
It has been shown that most minor elements are related to the
function of specific enzyme systems in the plant. As such, and
since they do not form a part of the plant tissue, they are needed
in extremely small amounts.
Q.-What special effect does potassium have on plant growth?
Potassium is needed in large quantity in the plant conducting
YouR FLORIDA GARDEN SOILS
tissues. Woody plants seem to have an extra high requirement for
potassium. Potassium is the "stiffener" for plant growth. It does
just the opposite of nitrogen. Instead of soft growth, potassium
promotes firm, erect plants and causes them to be more resistant
to cold and plant diseases.
Q. -What are the best soil conditions for African-violets?
African-violets like a potting mixture that is organic in nature,
fibrous in texture, and well supplied with plant food nutrients.
Subsurface watering and limited amount of light are also some
growth requirements for these plants.
Q.-What soil conditions are best for hibiscus?
Hibiscus soil should not be too wet or too dry and should have
a high content of organic matter. The fertility value of the soil
should be high and preferably on the sweet side (pH 6 to 7). A
good mulch of leaves will help in keeping a uniform soil tem-
perature and moisture.
Q.-Do hollies require special soil conditions?
Hollies have a wide range of soil preferences. Except for the
swamp species of holly, most hollies prefer a well-drained soil
covered with a thick mulch of leaves or pine needles.
Q.-Should I remove the paper pots from plants prior to planting?
This is not necessary. Roots will easily pierce the paper and con-
tinue to grow normally in the soil.
Q.-Is the County Agricultural Agent's office a good place to go
for a wide variety of agricultural literature?
The County Agent's office is an excellent place to go for both
state and federal literature on all phases of agriculture.
Q.-I have been told that the rows in my winter garden should
run north and south. Why is this?
One of several essential growth factors for plants is light. All
plants have their own special photoperiods. Some require long
periods of light and others require short periods of light. All
YOUR FLORIDA GARDEN SOILS
plants have a minimum requirement for the length of time they
must receive light for the manufacture of sugars and starches. By
running the rows of the winter garden north and south, each plant
is receiving as much light as possible from the winter sun which
is low in the southern horizon. If the rows were running east and
west, the shadow of the southernmost row would prevent light
from reaching other rows in the garden.
Q.-What is the purpose of clean cultivation around fruit trees?
Preservation of soil moisture. One of the greatest limiting factors
for tree growth is soil moisture. Weeds and other growth will
compete with the tree roots for available moisture.
Q.-Is there any danger in tilling garden soils too deep?
Deep tillage can be, harmful when it is necessary to till the garden
after the plants are fairly large in size. Tillage at this time can
cut many of the lateral feeding roots and harm the normal growth
of the plant.
Q.-Is sandy soil the only texture of soil good for citrus?
In frost-free areas, citrus will grow on many different soil types
provided they are properly drained, limed, and fertilized.
Q.-What are the soil factors that promote the best growth of
Some of the important soil factors are as follows:
1. Adequate soil moisture.
2. Good soil structure and texture.
3. Good organic matter content.
4. Enough plant food nutrients.
5. Good weed control.
6. Regular treatment for pests.
7. Proper soil drainage and aeration.
8. Adjustment of the soil reaction where needed.
Q.-Should the kind of plant determine how deep to plow the
Better yet, the kind of plant and the type of soil. Very fine-
textured soils that tend to pack near the surface are improved in
soil structure when they are plowed deep. Deep plowing allows
better soil aeration and root penetration for those plants that
naturally have a deep root system.
Q.-Should fertilizer be placed in the planting hole before set-
ting the plant or placed around the plant after it is planted?
If properly carried out, both should be done. The hole should
be dug deep enough so that a small quantity of mixed fertilizer
can be placed in the bottom and covered with soil. The plant is
placed in the hole and soaked with water. After the plant is well
established, a small circle of mixed fertilizer should be sprinkled
around the plant at about the leaf-drip once or twice each year.
Q.-What is meant by a split application of fertilizer?
When a basic fertilizer recommendation is applied in two or
more portions during the growing season, it' known as a split
application. For example, a 4-lb. recommendation of fertilizer is
applied as 2 lbs. during planting and 2 lbs. during the middle of
the growing season.
Q.-What is the difference between drilling and broadcasting a
Each method has its place in the garden program. Drilling is the
only practical method of applying fertilizer to row crops. It is
done by laying a band of fertilizer on each of the rows, 2 in.
to one side and 2 in. deep. Broadcasting has its place for lawns
and pasture, and involves the spreading of recommended amounts
of fertilizer uniformly over a prescribed area.
Q.-Is it true that plants grown with organic fertilizers are more
resistant to pests than plants grown with commercial ferti-
Plants receiving their nutrients in the proper amounts and pro-
portion from either organic or commercial fertilizer sources are
equally thrifty and resistant to pests.
YOUR FLORIDA GARDEN SOILS
Q.-What are nutritional sprays?
These are sprays containing one or more of the necessary plant
nutrients. Nutritional sprays are applied over the foliage of the
Q.-After I apply fertilizers to my plants, some of the leaf tips
turn brown. What is the cause of this?
This is known as tip burn. The brown tips are caused by too
high a concentration of soluble salts in the soil solution. Too
much of any kind of fertilizer can cause tip burn in plants.
Q. -Is there a special way to fertilize gladioli?
Yes. Gladioli require special care in fertilizing. Generally, they
are fertilized after flowering to furnish plant food elements to
be stored in the corm for the following year's growth. Young
bulbs require more fertilizer than older bulbs.
Q.-Should the fertilizer be placed as near as possible to the
seed or plant?
Never. This is a sure way of preventing germination of seeds
and killing plants.
Q.-The fertilizer I use seems to make my flowering plants grow
vegetatively and not bloom. What is wrong?
Either your soil is already high in available nitrogen or the fer-
tilizer you are using has too high a content of nitrogen in relation
to phosphorus and potassium. A combination of both, high nitro-
gen soil and high nitrogen fertilizer, can cause excessive vegeta-
tive growth of certain plants.
Q.-How can I reduce the cost of fertilizer application for my
There are several short cuts in which you may reduce the cost
of fertilizer application. Some of them are:
1. Use split applications of the basic fertilizer recommendation.
2. Use no more than the recommended amount.
3. Use high analysis fertilizer of the same ratio.
4. Grow a recommended legume as a green manure crop.
5. Apply the mixed fertilizer in bands on each side of the row
rather than by broadcasting.
Q.-My pecan trees are dying in part of my grove, yet all of the
land seems well drained. What is wrong?
This is a typical condition in areas where some form of hardpan
exists in the soil. Some soils may have a deep hardpan in one
section of the pecan grove and a shallow hardpan in another part
of the grove. Pecan trees need 3 ft. or more of well-drained soil
in which the root system can easily penetrate. When the hardpan
is close to the surface, the pecan trees gradually die.
Q.-I note the fine stand of clover along the roadside. Is this
due to the kind of soil it is growing in?
The good stands of clover found growing wild along the road-
sides in the spring of the year are due to several factors. Finer-
textured soils help, but the favorable moisture conditions and
the abundant supply of lime from the road bed probably have
most to do with the growth of this clover.
Q.-Do tin cans injure the roots of plants growing in them?
There is no evidence to show that the steel and tin coverings of
cans have any harmful effects on plants of any kind.
Q.-How do I keep my garden soil from packing?
Frequent shallow cultivation around your plants should keep the
topsoil loose and well aerated. If the garden is to be left fallow
for any length of time, it should have a suitable legume cover
crop growing in the soil. The cover crop will protect the surface
against beating rains and prevent packing.
Q.-Do weed killers leave residues in the soil?
Only for short periods of time. The directions on the container
indicate the residual effect of the specific weed killer.
Q.-Is it necessary to cultivate the soil in a heavily-mulched
YOUR FLORIDA GARDEN SOILS
Very little cultivation is necessary in a heavily-mulched flower
bed. A heavy mulch not only protects the surface soil from beat-
ing raindrops but also adds to the organic matter of the soil on
decomposition. Both of these factors help to keep the soil porous
and well aerated. Cultivation may be necessary where weed
growth has encroached on a mulched flower bed.
Q.-Should farm manure be used in garden soils?
Farm manure is excellent for garden soils. Fresh farm manure
should be worked into the soil well ahead of planting.
Q.-What do I use and how do I fertilize palm trees?
Use a common vegetable fertilizer such as a 4-8-8 with 1/2 or
more of the nitrogen in organic form. If the palms are planted
in open ground, broadcast the fertilizer under the spread of
leaves. If they are planted in the lawn, then plug the fertilizer
in by making holes around the tree with a crowbar and filling
the holes v*jh fertilizer. The amounts of mixed fertilizer may
be as small as 1 Ib. per tree for young palms to 20 lbs. per tree
for large palms.
Q. -How many essential nutrient elements are known to be
needed by growing plants?
Sixteen essential nutrient elements are now known to be needed
for normal plant growth. They are listed as follows:
MAJOR ELEMENTS MINOR ELEMENTS
Nitrogen Hydrogen Iron
Phosphorus Oxygen Manganese
Q. -Why do most hydroponic tomatoes seem firmer than those
grown in the soil?
Potassium is the plant food element that has a hardening effect
on tomatoes. In a system of controlled growth, such as that used
in growing hydroponics, it is a simple matter to keep the potas-
sium at high levels in the solution as compared to nitrogen. By
doing this, the fruit develops a high ratio of solids to moisture.
With proper soil tests, one may do the same with soils.
Q.-What plant nutrient tends to cause a plant to mature early
High amounts of phosphorus, in relation to other plant nutrients,
tend to cause a plant to mature early in life.
Organic Matter, Mulches and Composts
Q.-Are alt-organic soils sour?
No, not all organic soils are sour. Florida has many acres of
organic soils that are resting on marine limestone. These soils
have a very high content of calcium and magnesium and are
called sweet soils. These sois range from pH 6 to pH 7. When
organic soils are not influenced by limestone deposits, they are
Q.-Of what importance is humus?
Humus is a part of a true soil and has a tremendous influence
on the growth of plants. A few of the beneficial effects of soil
humus are as follows:
1. Benefits both the texture and structure of the mineral soil.
2. Supplies a large part of the nitrogen and phosphorus that
plants need for growth.
3. Helps maintain uniform soil temperatures.
4. Increases the moisture retention of the soil.
5. Makes other essential elements more available to plants.
6. Allows for rapid infiltration of rain water.
ORGANIC MATTER 63
Q. -What is the main source of organic matter in Florida soils?
The green mass of vegetation that covers Florida soils is the main
source. The amount of organic matter that accumulates will de-
pend on environmental factors such as air, water, temperature,
kind of soil, and kind and amount of vegetation.
Q.-Will a mulch increase soil acidity?
This will depend on the kind of mulch and depth to which it
is mixed with the soil. Very acid peats or mucks, when used as
a mulch, may cause the soil acidity near the surface to become
slightly more acid. The average leaf and pine needle mulch does
not affect the soil acidity to any degree, due to the rapid break-
down of the weak, organic acids as they enter the soil. Soils are
good buffers; it takes definite quantities of relatively strong acids
or bases to change their reaction to any degree.
Q.-Does a mulch supply any plant food nutrients
After a mulch begins to decay, it will start to supply several
valuable plant food nutrients. The most important is nitrogen,
with some potassium and phosphorus, as well as calcium and
magnesium. Some sulfur and minor elements can also be ex-
pected to be liberated from the more completely decomposed
portion of a mulch. Additional commercial fertilizer should be
applied to plants according to directions. The amounts of plant
food nutrients supplied by a decomposing mulch are generally
insufficient for normal plant growth.
Q.-Is it true that sawdust makes the soil very acid?
Work done by Allison and Anderson of the Agricultural Research
Service, United States Department of Agriculture, Beltsville,
Maryland, shows that the effect of sawdust on soil acidity is of
minor importance. The slight effect of adding acids to the soil
is due to the initially weak acidity of the fresh sawdust rather
than to accumulation of organic acids caused by normal decom-
position. For most plants, it may be advisable to add 1/2 lb. of
fine limestone to each bushel of fresh sawdust applied.
COMPOST BIN MADE OF CEDAR TWO BY FOURS
A PRACTICAL COMPOST BIN
I. SELECT A SHADY SPOT TO BUILD THE COMPOST BIN.
2. WITH EACH BUSHEL OF PLANT MATERIAL, MIX THREE CUPS
OF A 4-7-5 FERTILIZER AND 2/3 CUP OF FINELY GROUND
3. KEEP WELL AERATED AND MOIST BUT NOT WET.
4. IF THE COMPOST HEATS UP, FORK IT OVER TO ALLOW THE
HEAT AND EXCESS CARBON DIOXIDE TO ESCAPE.
ORGANIC MATTER 65
Q. -Will sawdust make a good mulch?
According to work done by the United States Department of
Agriculture, sawdust makes a good mulch if properly treated.
With each bushel of loose sawdust, mix 1/2 lb. of sulfate of
ammonia and 1/2 lb. of fine limestone prior to application. After
one month, sprinkle another / lb. of sulfate of ammonia over
the same amount of sawdust to take care of leaching and biotic
Q.-How is a satisfactory compost heap made?
See the illustration and formula in this chapter. In addition to
the formula given with the illustration and construction of the
bin, the compost heap may be improved somewhat by placing
the treated plant material in layers as follows: A layer of treated
plant residue 12 in. thick followed by a 1-in. layer of cow
manure or black garden soil. These layers are continued until
the bin is full.
Q. -What is a good formula for speeding up the rotting process
of a compost heap?
A simple formula is to mix thoroughly with 1 bu. of plant
material, 3 cups of a 4-7-5 or similar mixed fertilizer, 2, cup
of finely ground limestone, or 1 to 2 cups of wood ashes. The
addition of a little well-rotted cow manure will also hasten the
decomposition of the plant material in the compost heap.
Q.-Can I make compost with leaves only?
Leaves make an excellent compost. Since leaves are low in nitro-
gen, they should receive the generally recommended treatment
for any carbonaceous material. See the question on how to make
a compost pile, above, for details on supplemental treatment.
Q. -Why is the lower part of my garden soil black in color and
the higher part yellow in color?
In the lower part of the garden, the water table is nearer the
surface. During some months of the year in the lower levels, it
may be very near the surface. These wet soils are less aerated
25% CRACKED CHARCOAL
A SUPERIOR POTTING MIX
ORGANIC MATTER 67
than the well-drained soil occupying the slopes. Being less aerated
greatly inhibits the oxidation and subsequent loss of organic
matter. The black color in the lower part of your garden is an
accumulation of soil organic matter due to the higher water table.
The yellow color is hydrated iron oxide with very little organic
matter to mask it.
Q.-Are the roots of plants considered as crop residue? Do they
help my garden soil?
Roots of plants are excellent crop residues. There are several
important ways that plant roots help your garden. They may
be listed as follows:
1. The decay of plant roots helps maintain the organic matter
content of the soil.
2. Desirable soil structure is aided by the presence of both live
and dead plant roots.
3. Infiltration of rain and aeration are promoted by bbth live
and dead plant roots in the soil.
Q.-What is a good potting soil mixture?
In order to supply the necessary 1olloidal material and slowly
available nitrogen, a good potting mixture should include a high
percentage of organic matter. The mixture should hold moisture
well, yet be porous enough to allow good aeration and drainage.
A recommended mixture is 1/ loam, peat, sand, and
cracked charcoal. A small amount of mixed fertilizer blended in
with the above ingredients will improve and balance its nutrient
Q.-How can I build up the organic matter content of my garden
In Florida, with its favorable year around climate, it is very
difficult to build up the organic matter content of a properly-
drained garden soil. However, organic matter can be maintained
by selecting and planting certain legumes during off seasons.
These green manure crops, as well as other plant residues, are
turned into the soil, where they decay and replenish the existing
Q.-Is it better to put a good grade of peaty-muck on a lawn
before or after it is established?
Too many disappointing lawns are begun without the proper
preparation of soil. It is better to mix a good grade of peaty-muck
in the top 2 or 3 in. of the mineral soil before seeding or sprig-
ging. At this time, it is also advisable to take care of fertilizer,
lime, and drainage needs. However, if a lawn is started and it
is found that the soil is too light and not holding water or
nutrients, it is still beneficial to work a good grade of peaty-muck
into the grass sod.
Q.-What causes humus to form in the soil?
Humus is made up of the decomposed remains of plant and
animal lge. This includes mainly the macroorganisms and micro-
organisms of the soil plus the plant residues at the surface. Both
of these, soil organisms and plant residues are necessary to main-
tain the total organic matter content of the soil in Florida. When
grass and leaves are burned, they are prevented from returning
to the soil to augment the humus content of the surface layer.
Nature is still the best provider.
Q.-What makes a compost pile shrink so much?
While a compost pile is shrinking, it is gaining rapidly in unit
weight. There are several reasons why a compost heap reduces
size during decomposition. The principal one is the tremendous
loss of carbon in the form of the gas, carbon dioxide. The
microbes that are decomposing a compost heap need carbon as
a source of energy. They get it by decomposing and breaking
down the complex organic material in the compost heap. In the
process, the physical properties of the compost change from
coarse, dry material to a more finely divided, moist, spongy mass,
which has a tendency to become compact, thus reducing the size
of the pile.
YOUR FLORIDA GARDEN SOILS
ORGANIC MATTER 69
Q. -Which is the most practical way of adding humus to garden
soil? Should I grow it, make it, or buy it?
Grow it if your garden consists of a quarter acre or more. You
can add humus in the form of plant material with a small amount
of cost and labor by turning under a green manure crop. See your
County Agricultural Agent for literature and information on the
best leguminous crop to plant for your area. If the garden spot
is only a few hundred square feet, then it may be more feasible
to use compost or commercial peat rather than a green manure
Q.-Which makes the best mulch: Spanish moss, pine straw,
sawdust, or wood shavings?
One of the principal attributes of a good mulch is that it must
be slow in decomposing, have good physical characteristics, not
compete with cultivated plants for plant food elements, and add
to the fertility value of the soil on complete decomposition. All
of the mulches mentioned may be used, but only pine straw fits
all the qualifications mentioned. For example, if some available
nitrogen is not added to a sawdust or shavings mulch, organisms
decomposing it will compete with cultivated plants for this highly
Q. -I am told that the plant residues that I rake and burn are the
materials that cause humus to form in the soil. Is this true?
Yes, this is true. When leaves and grass must be raked, they
should be added to a good compost heap. The purpose of the
mulching attachment on your lawnmower is to pulverize the
grass clippings so they will filter back through the sod to help
replenish the humus in the soil.
Q.-What are the characteristics of a good green manure crop
for my garden?
There are several characteristics a good green manure crop should
possess. Some of them are:
1. It should be a leguminous crop so that nitrogen may be added
to the soil.
2. It should yield an abundance of green weight.
3. It should have a deep root system.
4. It should be nontoxic to animals.
5. It should be a good reseeder.
6. It should not encourage nematode development.
7. It should have a good canopy of top growth to protect the
Q.-What are the influences of organic matter on soil fertility?
Some important influences of organic matter on soil fertility are
1. Helps the soil to retain moisture.
2. Liberates several important plant food elements into the soil.
3. Causes plant food elements in soil minerals to become more
available to plants.
4. Makes the soil more porous and allows rain to enter freely.
5. Improves the soil structure so that it can be easily tilled.
6. Helps keep the soil temperature uniform.
7. Causes the soil to warm up earlier in the Spring.
Q.-Can I help maintain the organic matter content of my gar-
den soil by plowing under weeds and grass?
Yes, you can. Under natural conditions, weeds, grass, leaves, and
other plant residues are the only means nature has to maintain
the soil organic matter content. You can improve on these natural
conditions by selecting a recommended legume as a green manure
crop and turning it under.
Q.-What is the difference between green manure and cover
Green manure crops are generally selected leguminous plants
grown for the specific purpose of plowing into the soil. Cover
crops may be any selected plant grown during off season to
protect the surface of the soil from erosion and encourage infil-
tration of rain. Cover crops may be used for green manure by
turning them into the soil prior to starting a new garden.
YOUR FLORIDA GARDEN SOILS
Q. -My compost heap gives off a bad odor. Is this normal?
No, this is not normal but is easily corrected. When too much
water has been used on a compost heap, anaerobic conditions
exist, such as lack of enough free oxygen. Under these conditions,
the anaerobic bacteria liberate end products that have a disagree-
able odor. Under ideal conditions of moisture and air, the end
products are carbon dioxide and water with little or no odor.
An excess of watering is one of the most common errors in com-
post heap care. When undesirable odors are detected, the amount
of watering should be reduced. Or, if it is during the rainy
season, some type of cover should be used to reduce the amount
of water entering the heap.
Q.-Should I dig a pit in order to start a compost heap?
Because of the tendency for material to accumulate in the pit
and slow down the decay of the compost material, pits are gen-
erally not recommended. It is preferable to pile the compost on
flat boards, in a bin above the ground, or flat on the ground. In
this fashion, the compost heap is better aerated and it is easier
to control moisture conditions.
Q.-Could I make a compost heap with the leaves and grass that
I spend endless hours raking and burning?
The very leaves and grass you rake and burn are the only
materials that nature has for making that highly prized dark
substance in the surface of all productive soils. Leaves and grass
that cannot be mulched and must be removed from the surface
of the lawn should be added to a compost heap.
Q. -How is it possible to start with one ton of dry material and
finish with two or three tons of finished compost material?
As the volume of a compost heap decreases, the weight increases.
Much of the weight of the finished product is the dead cells of
the decayed organisms plus moisture. All of this is a very desir-
able part of composting. The plant food in the finished compost
is many times greater than in the original plant residues. Also,
the physical structure of composted materials is more desirable
than that found in the materials that are not composted.
Q.-Should fertilizer be added to compost piles?
Mixed commercial fertilizer added to a compost pile is beneficial.
Fertilizers give an extra amount of plant food nutrients and tend
to balance the nitrogen-phosphorus-potassium of the compost
heap. The result is a speeding up of decomposition with a
superior final product. About 1 cup of a good mixed fertilizer
to 1 bu. of plant material should be sufficient to aid in the
Q.-Are peanut hulls a good mulch?
Peanut hulls make an excellent soil mulch. Besides being a satis-
factory mulch, peanut hulls also liberate a fair quantity of potas-
sium upon decay. This is one of the essential plant food elements
used by plants in large quantities.
Q.-What are some forms of organic matter to incorporate into
my front yard for better grass?
Some well-known organic matter sources and recommended
amounts to use are as follows:
1. Granulated peat moss-3 medium-size bales per 1000 sq. ft.
2. Well-rotted cow manure-2 to 3 cu. yds. per 1000 sq. ft.
3. Commercial humus-2 to 3 cu. yds. per 1000 sq. ft.
Q.-What is the difference between peat and muck?
Peat is composed of partially decomposed plant residues and is
brown in color. Muck is well-decomposed plant residues and is
black in color. Both are true organic soils and have over 20 per
cent of the soil material, by weight, made up of plant residues.
Q.-Will the commercial black plastic mulch keep down weed
Since light cannot pass through the black plastic, it will keep
down weed growth. Weeds need an abundance of light for normal
growth. Without it, they cannot compete with cultivated plants.
YouR FLORIDA GARDEN SOILS
Q. -Will the addition of cow manure to a compost pile hasten
The addition of cow manure should hasten the initial stages of
decomposition of the compost pile. Cow manure has a naturally
abundant flora of cellulose digesting organisms that should act as
a good inoculant for the compost heap. Cow manure will also
supply some of the nutrients necessary for microbe activity,
Q.-In a compost heap, will some plant residues decay faster
Yes. The rate of decomposition will depend on the kind and age
of the plant. Plants that are younger or more succulent in nature
will be the first to decay. Your compost heap needs both fast-
and slow-decaying plant materials.
Q.-What is the difference between humus and organic matter?
All humus is organic matter but not all organic matter is humus.
Organic matter includes the partially decomposed plant material
at the surface of the soil, as well as the well-decomposed plant
material that is mixed with the mineral portion of the soil.
Humus is generally referred to as stable organic matter; further
decay is very slow. It is the material that gives mineral soils a
dark brown or black color near the surface.
Q.-Will leaves make a good compost heap?
Leaves make an excellent compost heap. Treat them just as you
would any plant material used for composting.
Q.-Is it advisable to incorporate some organic material before
trying to establish a garden on light sandy soils?
Yes, it is desirable. Any partially decomposed material would be
better than none. The better practice would be to grow a very
heavy green manure crop, such as blue lupine during the winter,
or hairy indigo or cowpeas during the summer, and turn the
crop under about one month prior to planting. Be sure to select
a variety of legume that is adapted to your area.
Q.-Is it worth while to spread a layer of muck over my garden?
If the garden is small and sandy, it may be helpful to spread
2 or 3 in. of muck over the area. If the muck is strongly acid,
it should be treated with lime, or spread and then limed, which-
ever is most convenient. The muck should be incorporated with
the top 6 in. of soil. Since the muck is already well decomposed,
there need not be any waiting period prior to planting.
Q.-Will a deep mulch protect plants from cold?
This depends on the part of the plant you wish to protect. If
only the roots are to be protected, then the mulch under the
plant will accomplish this. If the tops are to be protected, then
the mulch must cover the whole plant.
Q.-I burn every bit of plant residue that I can rake up. Is this
Plant residues are the principal way nature has of adding organic
matter to the soil. It would be a much better practice if these
plant residues were added to a compost heap, and eventually
returned to the soil.
Q.-Will a top-dressing of any organic material benefit my lawn?
This depends on the condition of the lawn grass. If the grass is
growing on a coarse-textured soil low in organic matter, then an
application of some well-decomposed peat will be beneficial. The
principal purpose of the peat is to aid the soil in holding moisture
and slowly to liberate available amounts of nitrogen. The avail-
able nitrogen helps to keep the grass a more uniform dark green
Q.-What are some reasons for composting?
A completed compost is synthetic manure. According to Waks-
man and Martin of Rutgers University, it is as good as any farm
manure. To list all the advantages and reasons for composting
would fill a book. However, a few important ones are given:
1. It is one of the best ways of returning organic material to the
YOUR FLORIDA GARDEN SOILS
ORGANIC MATTER 75
2. It adds valuable plant food nutrients to the soil in the form
that plants can utilize best.
3. It improves tilth and moisture conditions of the soil.
Q.-What materials can I use to make a compost heap?
Contrary to many rumors, you can use any plant residue to make
a compost. Some common ones are grass clippings, sawdust,
leaves, stems, and peanut hulls. Also, green residues such as
weeds, nonwoody hedge and shrub trimmings, harvested vines
and plants from the vegetable garden, and many other materials
may be added. Succulent materials decompose rapidly and, as a
result, furnish nutrients for the microorganisms responsible for
decomposition, thus speeding the entire process.
Q. -Can I use sawdust to add organic matter to soils?
In Florida it may be difficult to increase the organic matter in
soils. However, it is possible to maintain the organic matter con-
tent at a satisfactory level. According to Allison and Anderson
of the U.S.D.A., sawdust may be used to maintain the organic
matter content of soils. Regardless of the use made of sawdust,
it should receive supplemental nitrogen at the rate of 1.5 per
cent. This is equivalent to about 150 lbs. of ammonium sulfate
per ton of fresh material. If the soil is already too acid, then a
supplement of 100 lbs. of fine limestone should also be added
to the ton of fresh sawdust.
Q.-Should I leave lawn clippings on my lawn?
If it is possible to cut up grass clippings fine enough, they should
be left on the lawn. Generally, this can be accomplished with a
special mulching attachment that comes with most of the newer
mowers. The only reason for raking lawn clippings off the lawn
is that they may be too thick, thus shading the growing grass
underneath. If a lawn is mowed at regular intervals with a
mulching attachment, there is no reason for removing clippings.
Those that are left filter down into the soil, where they decom-
pose and return plant food elements and humus.
YOUR FLORIDA GARDEN SOILS
Q.-What is the simple chemistry of a rotting compost heap?
A great variety of soil microbes takes part in the decay process
of a compost heap. To encourage the rapid growth of these soil
microbes, the compost is stacked and treated. By splitting the
complex organic compounds to simple ones, they seek both energy
and food from the compost. In brief, with proper amounts of
air, water, carbon, and nitrogen from the compost heap, the
microbes build their own cells, liberating carbon dioxide and
water. After several months, the mass is greatly reduced in size.
At this time, the oxidation process slows down and the compost
material is ready to use.
Q.-What causes a compost heap to heat? Is this harmful?
Decomposition of the compost heap is a microbial process. Similar
to a slow-burning fire, oxygen is consumed and carbon dioxide
is liberated. If it were not trapped in the center of the compost
pile, the heat expended from decomposition would not be de-
tected. This heat can accumulate to a degree that would kill the
microbes that create it, and, in turn, slow down further decom-
position. To correct this situation, fork the compost heap over
and allow fresh air to enter and the heat to escape.
Q.-What is green manure?
When any crop is grown for the specific purpose of being turned
into the soil to augment its fertility value, it is termed a green
manure crop. Generally, leguminous crops are used for this.
Q.-Are pine needles as good as oak leaves for mulching plants?
Pine needles are excellent material for mulching plants. They
have a thick waxy surface that tends to retard decay, making the
pine mulch last longer than the oak leaf mulch.
Q. -Why are mulches recommended for nearly all plant beds?
It is often said that a "green thumb" belongs to the gardener who
knows how to use a good soil mulch. If there were a single
cultural practice that favored the greatest number of plant growth
factors, it would be a good mulch. Some of its benefits are:
1. A good mulch maintains a uniform soil temperature.
2. The soil retains as much as 2 or 3 per cent more moisture.
3. A mulch adds organic matter to the soil which, in turn,
favors beneficial microbial activity.
4. It helps keep down weed growth.
Q.-Organic growers claim that a plant can be grown so thriftily
that disease and insect pests are no problem. Is this true?
There is no scientifically proven evidence to show that plants are
any more thriftily grown organically or that pests are selective in
their choice of weak or thrifty plants to attack. It should be
remembered that any and all plants need the 16 essential plant
food elements in certain amounts and proportions, regardless of
whether they receive them from organic or inorganic sources.
Q.-What is humus?
Soil humus will be observed when the top layer of undecomposed
plant remains is moved from the surface of the soil. Humus is
well mixed with the mineral portion of the soil, giving it a black
or brown color. Its origin is the plant and animal remains that
have undergone extensive decomposition and have reached a
carbon-nitrogen ratio that prevents further rapid decomposition.
This "slow fire" is fed by the partially decomposed plant residues
near the surface. Humus is the natural home of billions of tiny
soil microbes that use carbon to build their bodies and as a source
of energy. Humus is a valuable part of our Florida sandy soils
and should be maintained.
Q.-I have been doing what neighbors have been doing for
years-burning all the plant residue that I can. Will this
method improve my sandy garden soil?
By not allowing plant residues to replenish the organic matter
that is lost by oxidation, you are depriving the soil of the most
valuable ingredient it can have. One needs only to observe the
dark color of the top soil to realize that it had its beginning from
plant residues, as well as from animal residues. Why defeat the
balance of nature by not returning plant residue to the soil?
g FIVE 5
Moisture and Temperature
Q.-Is irrigation of vegetable gardens desirable?
Nothing is more satisfying or offers better dividends than a good
system of irrigation for the Florida home garden. There are few
soils that cannot stand the extra amount of moisture needed to
keep plants at peak growing conditions. During Florida's dry
spring season and for sandy garden soils, this is especially true.
Q.-Is rain water the same quality as water from a home supply?
No, it is quite different. Except for a small quantity of dissolved
CO2, rain water is nearly distilled. The weak carbonic acid makes
the rain water slightly acid. Either naturally or by special treat-
ment, your home supply water will have a much higher content
of dissolved salts.
Q.-Should water from the washing machine be used around
It is not wise to use soapy water around plants. Most soapy
water is quite alkaline and, in time, will upset the favorable pH
balance of soil. Soapy water also tends to be detrimental to good
MOISTURE AND TEMPERATURE
soil structure. By constantly using washing machine water, soil
porosity is reduced and favorable soil aeration is impeded.
Q.-At what stage of growth is the greatest amount of water
required by garden crops?
During the earlier vegetative stage, when cell division is at its
peak, the greatest amount of water is required, the quantity
depending on the size of the plants grown. A large garden of
tomato plants requires frequent rains to keep them turgid prior
Q. -How much water does it take to grow 100 bu. of corn per
It is estimated that it takes about 500,000 gallons or about 20
in. of rain to produce 100 bu. of corn on one acre.
Q.-Why does the soil on the west side of my house dry out so
The soil on the west side of your house is heated all day long by
the sun. If there are no shade trees to prevent it, the sun strikes
the soil early in the morning and late in the afternoon. When
subject to prolonged heat, any soil, especially sandy soil, gives up
its surface moisture quickly by evaporation.
Q.-After the surface of my garden begins to dry out, what
causes the soil moisture to move up?
As the surface soil dries out and the water film around each soil
particle becomes thinner, it creates a force called tension. This
thinner film of moisture pulls moisture from the thicker film of
water located deeper in the soil. The area around the roots of
plants creates the same kind of tension as the roots remove
moisture from the soil. This is a desirable process in keeping
plants supplied with a steady flow of available moisture.
Q.-When discussing the movement of moisture in garden soil,
what is the difference between percolation and leaching?
Percolation is the normal movement of rain water through the
soil. The rapid infiltration of rain water and its subsequent per-
II II II
I I I I II
II II II
SOI !i i !BSOPTON '!3''
THE MOISTURE CYCLE
MOISTURE AND TEMPERATURE
colation down to the water table is a highly desirable process.
Leaching is a term used to express the loss of plant food elements
and other valuable soil materials when the percolation of water
through the soil is excessive.
Q. -My neighbor has the same type of soil that I have, yet water
stands on my soil much longer than on his. What causes
The difference is in soil structure which pertains to the arrange-
ment of soil particles. Soils that have been properly managed will
have good soil structure. These soils will be porous and allow for
rapid infiltration of rain water. Under the impact of beating
rains, soils that are left fallow with no plant cover for protection
will soon puddle or seal. Once the surface soil is sealed, the rain
water remains on the surface where it is lost by evaporation or
runoff. See your County Agricultural Agent for a good soil-
management program for a garden.
Q.-What is meant by a waterlogged soil?
When drainage is so poor that there is insufficient air for normal
root development, the soil is said to be waterlogged. Under these
conditions, the pore space in the soil is full of moisture, even at
Q.-How can a heavy clay soil that remains wet be drained?
These soils are drained satisfactorily by the proper installation
of suitable drain tile. Your County Agricultural Agent has printed
directions on how to lay drain tile. This procedure is expensive
and should be planned carefully.
Q.-What have hills and slopes to do with temperature of the
As well as affecting the temperature of the soil, hills and slopes
have a great deal to do with temperature of the air. Cold air is
heavier than warm, thus remaining near the surface or drifting
down the slopes to lower levels by movement of wind and gravity.
At the same time, warmer air, favoring high levels of ground,
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USE A GOOD MECHANICAL SPRINKLER TO WATER THE GARDEN OR LAWN
MOISTURE AND TEMPERATURE
rises above cold air. Consequently, frost remains in pockets and
low ground long after frost has melted on higher ground. Soil
that is exposed on slopes facing the south is warmer than soils
existing on northern slopes.
Q.-Which side of a lake in Florida is the warmest?
The south side of Florida's lakes is warmer than the north side.
The larger the lake, the greater the effect on air temperature.
Water is one of the slowest substances to warm up or cool off.
Long after the air above has cooled, lake water retains its heat.
A cold north wind blowing over water of a higher temperature
will be affected, thus carrying an acquired warmth over land on
the south side of a lake.
Q.-Should plants be watered before or after fertilizer is applied?
Always apply fertilizer first, washing it immediately into the soil
with a sprinkler. If left for any length of time on a plant, dry
fertilizer on a dry leaf will cause severe tip burn.
Q.-Can I make a good rain gauge?
You certainly can. An empty coffee can makes an excellent rain
gauge. An inch of rain water in a coffee can is an inch of rainfall.
Q.-What are the principal requirements of a good garden
In choosing a garden sprinkler, a most important prerequisite is
one large enough to cover the desired area to be sprinkled. It
should require as little mechanical maintenance as possible and
should deliver a spray with drops that are small enough to
prevent the soil from puddling or sealing over. An efficient
sprinkler should deliver ample water for wetting the top 3 or
4 in. of soil in a reasonable length of time.
Q.-The roots from my shade trees are competing with shrubs
for soil moisture. Should these shrubs be given additional
Yes. Since both shade trees and shrubs are valuable assets to a
YOUR FLORIDA GARDEN SOILS
home environment, sufficient water should be supplied for both.
To further conserve soil moisture, a heavy mulch around the
shrubs is desirable.
Q.-Is it feasible to purchase one of the new testing instruments
for checking moisture conditions of a garden?
For the average home garden, it is doubtful if such instruments
are worth while. One of the best moisture testing instruments for
a home garden is the hand trowel. A good sturdy one may be
purchased for approximately 50 cents. If the trowel reveals that
the top 3 or 4 in. are well-moistened, the garden is properly
Q.-How can I speed up the drainage of water from flatwoods
The number and depth of drainage ditches have much to do
with the rate and volume of water removed from flatwoods soils.
By digging ditches deeper, the water table is lowered in the
immediate area. For literature on properly draining a typical
Florida flatwoods soil, see your County Agricultural Agent.
Q.-What effect does too much water have on the growth of
Too much water may have several detrimental effects. Some of
1. Too much water may cause excessive dilution and leaching
of plant food elements from the soil.
2. Plants become spindly and unthrifty looking.
3. Too much water may block out sufficient air in the soil for
Q.-Should I refrain from watering plants during the heat of
It does not matter whether plants are watered at midnight or at
noon. In either case, the plant is subjected to no harm. The best
reason for watering after the sun is low on the horizon is related
to air temperature. During the heat of the day, humidity is low
MOISTURE AND TEMPERATURE 85
and evaporation high. Much water is lost that otherwise goes
into the soil, thereby becoming unavailable to the plant. The
opposite is true at night. Humidity is high and evaporation low.
Q.-Why are black sands harder to drain than light sands?
Pore spaces in black sands are partially filled with organic matter,
thus preventing rapid percolation and movement of water through
the soil. Once drained, these same black sands retain soil moisture
longer between rains.
Q.-I have noticed that during a prolonged dry spell some of
the younger plants wilt after they are watered with a supple-
mental water supply. What is the reason for this?
In all probability, wilting of young plants during a dry spell and
after watering indicates that supplemental water is high in total
dissolved salts. Because of the diluting effect of local rainfall, they
did not wilt at other times.
Q.-Is it feasible to install an irrigation system for a lawn?
This depends on the size of the lawn. If the area is one acre or
more, an irrigation system is practical. A properly installed lawn
irrigation system does a more efficient and thorough job of water-
ing than the manual method.
Q.-The more I fertilize my garden, the healthier the weed crop
and the more frequent irrigation necessary. What is taking
Weeds, nature's own moisture pumps, are using the moisture
cultivated plants should have. By removing weeds, you remove
competition, thereby conserving on the moisture, and possibly
cutting the amount of irrigation in half.
Q.-How much and how often should plants be watered?
This depends on the type of soil and the kind of plants to be
watered. Heavier soils, such as loams, hold larger quantities of
water over a longer period of time than sandy soils. After water-
ing, all soils should be moist to a depth of 4 or 5 in. For
determining when to water plants, use a sturdy hand trowel to
open the soil for a visual inspection.
Q.-Are soils near the coast warmer than soils in the interior of
Yes. Soils near the coast in Florida are modified indirectly by the
Atlantic Ocean on the east coast and the Gulf of Mexico on the
west coast. These large bodies of water warm the air above them.
In turn, this warm air moves in and modifies the soil temperature
near the coast. In winter, cold waves from the north counteract
this warm air movement by sending long tongues of cold air
down the central ridge portion of the state.
Q. -What can be done about a boggy, wet area in a garden?
This calls for good water management. Although we should be
careful not to overdrain in sandy soils, there are times when
drainage is necessary. Some low boggy spots may be easily filled
in with a sandy texture of soil. When there is enough fall, they
may be successfully drained. On the other hand, when there is
little or no fall, a deep ditch, or tile drain, may be used for
dropping the local water table to a desired level for at least a
portion of the year.
Q.-Are weeds serious competitors for soil moisture?
Weeds compete directly with cultivated plants for soil moisture.
More water is removed from garden soil by weeds than by any
Q.- I have a well-drained sandy soil for a garden plot. Should
I rely wholly on rainfall for irrigation needs?
Florida has sufficient rainfall which, unfortunately, comes at the
wrong time of the year for most garden needs. Consequently,
having a supplemental irrigation system is almost a necessity.
For most soils in Florida, an irrigation system will prove its worth
Q.-What is a practicable procedure for using irrigation water
high in soluble salts?
YOUR FLORIDA GARDEN SOILS
MOISTURE AND TEMPERATURE
Salty irrigation water should be used at more frequent intervals
than water containing a low content of dissolved salts. This is
done to prevent the concentration and accumulation of salts in
the soil. Only a few plants will tolerate a relatively high concen-
tration of soluble salts. Any irrigation water with 2,000 parts per
million or more of total dissolved salts can be toxic to plants, and
should be used with caution.
Q.-What is meant by the seep method of irrigation?
For some gardens that rest over marl or clay, it is possible to
irrigate by digging ditches between the rows of plants. The irri-
gation water percolates down to the marl or clay where it is held
and allowed to seep in a lateral direction toward the plant roots.
For gardens of this type, overhead sprinkler systems are un-
Q.-I have been told that there is moisture in garden soil even
after plants wilt. Is this true?
Yes, this is true. For most Florida soils, the amount of moisture
may be about 2 or 3 per cent by weight. These thin films of
moisture are held so tightly by soil particles that they are not
available to plants.
Q.-What is the overhead method of irrigation?
Any method where sprinklers are used to irrigate the soil is
termed overhead irrigation. For most sandy garden soils, this sys-
tem is recommended.
Q.-Which is the most detrimental to plants: sprinkling too
little or too much?
Both are bad. Sprinkling too little causes plant roots to grow
near the surface where they quickly dry out. Sprinkling too much
will, in time, leach the available plant food elements out of the
topsoil. Wetting the soil with enough water to maintain a deep
root system is the best irrigation practice.
Q.-My well water is slightly brackish. Will this affect the
fertility of soil?