Title Page
 Table of Contents
 Part I. Selection and planting
 Part II. Maintenance of dooryard...
 Historic note

Group Title: Bulletin - University of Florida Cooperative Extension Service ; 166C
Title: Citrus fruit for the dooryard
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00020524/00001
 Material Information
Title: Citrus fruit for the dooryard
Series Title: Bulletin - University of Florida Cooperative Extension Service ; 166C
Physical Description: Book
Language: English
Creator: Lawrence, Fred P
Lawrence, Fred P.
Publisher: Cooperative Extension Service, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1972
 Record Information
Bibliographic ID: UF00020524
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltqf - AAB2788
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Table of Contents
    Title Page
        Page 1
    Table of Contents
        Page 2
    Part I. Selection and planting
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
    Part II. Maintenance of dooryard citrus
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
    Historic note
        Page 21
Full Text


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MAY 1972

3 Part I-Selection and Planting
3 Climatic Divisions
3 Soils
4 Choice of Rootstock
6 Choice of Scion for Budwood Varieties
6 Early Maturing Varieties
6 Midseason Varieties
7 Late Season Varieties
8 Grapefruit
9 Acid Fruits
9 Other Citrus
10 Planting Site
11 Selecting the Tree
12 Planting
14 Part II-Maintenance of Dooryard Citrus
14 Care of Non-bearing Trees
14 First Year
16 Second Year
16 Third Year
16 Fourth Year
17 Care of Bearing Trees
17 Fertilization
18 Cultivation
18 Pruning
19 Irrigation
19 Cold Protection
20 Fruit Splitting

We are deeply grateful to those at the University of Florida,
the Citrus Experiment Station in Lake Alfred and the
USDA Horticultural Station in Orlando whose respective
ideas and suggestions were of great value in preparation
of this Bulletin. We also acknowledge with thanks specimen
plants supplied for photographs by the Grand Island Citrus
Nursery Co. and Hall's Nursery of Eustis, Florida.

(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
United States Department of Agriculture, Cooperating
Joe N. Busby, Dean

Citrus Fruit For the Dooryard
Fred P. Lawrence
Citriculturist, Agricultural Extension Service

Part I -Selection and Planting

Dooryard citrus plantings com-
plement Florida living. They pro-
duce fruit of excellent food value
which can be stored on the tree
for long periods without loss of
nutritional qualities, and they are
beautiful evergreens which en-
hance the beauty of the grounds
and increase property value. Prop-
erly handled, the plantings can be
made to blend with the overall
landscape and produce an abun-
dance of delicious fruit.
This bulletin has been prepared
to assist the home-owner in choice
of stocks and scions for effective
plantings and to give helpful sug-
gestions on selecting a planting
site, on preparation of the soil and
on planting. For those who already
have bearing trees a cultural pro-
gram designed to keep the trees
at maximum productivity is offer-
Climatic Divisions
Florida may be divided into
three general climatic zones -
southern, central and northern.
These areas may be fairly well de-
fined by drawing a line across the
state from Sarasota on the west
coast to Ft. Pierce on the east
coast; the area south of the line
may be called southern Florida.
From this line north to a second
line drawn from Brooksville
through Ocala to Crescent City

may be described as central Flor-
ida. From this line north and west
should be called northern Florida.
Citrus will grow well in southern
and central Florida. However,
within these districts there may
be local areas where citrus cannot
be grown satisfactorily. The entire
northern Florida area is generally
unsuited to citrus, due to low win-
ter temperatures, although there
are certain locations within this
area where the hardier stocks and
varieties will survive.
Florida soils generally fall into
one of four broad classifications -
sands, mucks, marls, and the rocky
soils of the southern tip of the
peninsula. By far the greatest ex-
panse of soils falls into the "sands"
classification. For citrus growing,
sands may be further divided into
three types (1) the deep,
drought sands found in the cen-
tral coastal dunes and also in
the sand scrubs of the interior;
(2) the rolling, well-drained sands;
and (3) the poorly drained flat-
woods lands, frequently underlaid
by hardpan.
Citrus can be grown with a min-
imum of soil preparation on well-
drained lands. It also can be grown
on most other types where drain-
age and irrigation can be provided.
Where drainage is not practical,

special soil preparation, such as
bedding or mounding prior to
planting, may be required. Mounds
should be at least 12 feet in di-
ameter at ground level, a minimum
of 18 inches high (36 inches in wet
locations), and eight feet in di-
ameter on top.

Choice of Rootstock

Citrus fruits do not always re-
produce true to type through seed.
They are best propagated by some
vegetative means, such as by cut-
tings or layering, or by grafting
or budding onto a rootstock of
some closely related species or
type. In Florida, the customary
method of propagation is by bud-
Rootstocks may be chosen to
suit the climatic conditions, the
soil type, the scion' varieties, and
the landscape.
For Climatic Area. The five
rootstocks commonly used in Flor-
ida, in order of their hardiness or
resistance to cold, are Trifoliate
orange, sour orange, sweet orange,
Cleopatra mandarin, and rough
lemon. The exceptional cold hardi-
ness of trifoliate makes it a de-
sirable rootstock for most varie-
ties in home plantings in northern
Florida. The fruit produced by va-
rieties budded onto trifoliate
stocks is of excellent quality. A
hardy, cold-resistant stock has a
tendency to render a tender scion
more hardy.
For Soil Ty p e. Trifoliate
orange is well adapted to a wide
1 Pronounced "sigh-on". This is the term given
to budwood.

range of soils. Sour orange or tri-
foliate is recommended for heavier,
poorly drained soils. Rough lemon
is suited to high, dry, sandy soils.
Cleopatra and sweet orange are
best suited to the intermediate
soils, but Cleopatra can be used
on the heavier soils and sweet
orange on the drier ones with a
fair degree of success.
For Variety. Under normal
conditions, the five stocks under
consideration are compatible with
all the more common varieties, but
a degree of choice can be express-
ed. Rough lemon produces large
trees faster on well drained soils
and is a prolific bearer, but the
fruit is of poorer quality than fruit
grown on other stocks. Rough
lemon is not recommended for low,
heavy, poorly drained soils, due to
its susceptibility to foot rot; it is
also one of the least cold-resistant
stocks. If used in a home planting,
rough lemon is best suited as a
stock for Valencias. Cleopatra is
especially recommended for man-
darin type fruits, trifoliate for
satsumas, and sour and sweet
orange stocks for other varieties.
For Landscape Design. Un-
budded seedlings of sweet orange

- 2'-

produce slender upright trees for
the first 10 to 12 years, often
reaching a height of 20 feet or
more. About the twelfth year the
trees begin to spread and, if not
crowded, may reach 40 feet or
more in canopy and height. Dur-
ing this time lower limbs may be
removed to form umbrella-like
shade trees. Sweet seedlings be-
gin to bear fruit at seven to nine
years and the yield gradually in-
creases until they are approxi-
mately 30 years old.
Budded trees are low and com-
pact in growth habit. However,
they, too, ultimately will reach a
height of 20 to 30 feet, with a 30
foot diameter if not crowded. Most
varieties when budded on trifoliate
stock, produce a semi-dwarf tree.
These are slower in growth habit,
resulting in somewhat smaller
trees than those produced on other
commercial stocks.
Kumquats are quite decorative
and seldom exceed 15 feet in height
on any stock; the calamondin al-
so is a smaller tree. Where a small
tree is desired both of these va-
rieties should be placed on trifoli-
ate stock. Severinia buxifolia, a
citrus relative extensively used as
a hedge plant, can be used also as
a rootstock for most varieties to
produce dwarf trees. This particu-
lar plant is not used extensively
as a rootstock, due to lack of de-
mand, and it is difficult to obtain
with citrus varieties grafted onto
it. Otaheite orange is a true dwarf
citrus. It is grown in northern
greenhouses as a potted plant but
there is little demand in Florida,

Fig. 1.-Upright growth habit of a
seedling tree. Between 15 and 20 years
of age, if not crowded, the tree fills out
and becomes a large, symmetrical and
beautiful one. (The tree in this picture
is 4 years old.)

Fig. 2.-Young budded tree (4 years
old). -It too will grow into a large,
symmetrical tree.


possibly because of its insipid
taste. It should be grown for
ornamentation only.
Under normal conditions, the

home-owner will produce more de-
sirable fruits when his trees are
grown on sour orange or Cleopatra
mandarin rootstocks.

Choice of Scion (or Budwood) Varieties

In Florida there are many va-
rieties of citrus, including experi-
mental hybrids, but relatively few
are used commercially. This leaves
a group of exotic and delicious
varieties from which the home
gardener may select to produce
something unusual in flavor. It is
recommended that the home-own-
er grow these more exotic fruits
since other varieties are plentiful.
Some of these are listed in the
order of their season of ripening,
to enable the dooryard grower to
select varieties that will produce
fruit over the longest possible

Early Maturing Varieties
Satsuma. The satsuma on
trifoliate stocks is possibly the
most cold resistant of the com-
mercially grown citrus varieties in
Florida. This combination of stock
and scion does well on a wide range
of soils and will grow in all citrus
areas of the state; however, the
fruit is of best quality when
grown in the more northern sec-
tions. The fruit retains its peak
quality for only a short time and
if not picked in 10 days or two
weeks after peak maturity it be-
comes puffy, rough in appearance
and insipid in taste. There are
many strains of the satsuma; one

of the most satisfactory is the
Navel.-Florida has many fine
varieties of navel oranges. They
produce large, juicy, delicious seed-
less fruits that are wonderful for
salads or for eating out of hand.
Among the better varieties are
Barringto n, Summerfield and
Nova Tangelo. The fruit is
earlier ripening, sweeter and more
highly colored than the Orlando
tangelo. It is of medium size, with
a smooth orange-colored peel that
is close fitting but easily removed.
It ripens in October and reaches
its prime in November.
Osceola Tangelo. It is an ex-
ceptionally high-colored, orange-
red, tangerine-type hybrid that
produces heavy crops of beautiful,
delicious fruit. This variety is at
its best in November.
Additional Early Varieties. -
Such varieties as Orlando, Lee,
Robinson and Page could very sat-
isfactorily be substituted for or
planted in addition to the Nova
and Osceola.

Mid-Season Varieties
Minneola Tangelo. The Min-
neola Tangelo is of good rich
orange-red color and has excellent
flavor and very few seeds. In iso-


lated plantings it tends to be shy
bearing but it is a beautiful tree
and usually bears ample fruit.
Temple.-The Temple orange is
one of the most beautiful and
highly-flavored citrus fruits. The
tree is willowy, compact and quite
attractive. The spice-like fruit
have a deep-colored, pebbled peel
that tends to be smooth and tight
when grown on heavier, more cal-
carious soils. The Temple is at its
best in February and March.
Murcott Honey Orange. Un-
like its exact origin, the superior
quality of the Murcott Honey
Orange is well known. It resembles
the ordinary tangerine but the peel
is not as deeply colored as the
Dancy tangerine. Its deep orange-
red flesh is firm and possesses am-
ple rich, sweet juice. It peels easily

and can be eaten from hand. Its
worst feature is a rather large
number of large, well-developed
seeds. This fruit is at its best in
late January and February.
Additional Mid-Season Varieties.
- Such varieties as the Dancy
tangerine, Ponkan and Clementine
could be added to or substituted
for these mid-season varieties.

Late Season Varieties
King Orange. Actually the
King is a large mandarin. It is the
latest maturing "Kid glove" va-
riety grown in Florida. It is large
and has an oblate shape. The peel
is deep orange in color, thick,
rough and loosely attached to the
segments. The tree itself tends to
be less compact and more nearly

Fig. 3.-Bill Mathews and Howard Hartle admire a beautiful compact tree of
Orlando Tanirelos.

Fig. 4.-The persian or green lime
grows well in the warmer locations of
southern Florida.

resembles an orange tree than a
mandarin in appearance. The tree
does not bear heavily, but the fla-
vor and quality of its fruit tend to
compensate for this less desirable
feature. The King is at its best
in March and April.
Valencia.- This is the standard
commercial variety of round or-
anges in Florida. Although it is a
standard commercial variety, the
Valencia is recommended to home-
owners who wish to have fresh
fruit well into the summer. The
fruit are large and nearly seedless.
The peel is deep orange, and the

orange-colored flesh is firm with
good sweet juice. It is primarily a
superior-quality juice orange. The
Valencia is in season from March
until September; however, it
reaches peak maturity in June.

Royal.-The Royal differs from
typical grapefruit varieties in that
the fruit is slightly smaller and
has a darker orange-yellow color.
The juice is sweeter than that of
most grapefruit and the rag is
less bitter and has a milder odor.
Triumph.- Neither the Royal
nor the Triumph is grown commer-
cially in Florida. However, the
quality of these fruits is recog-
nized as exceptionally good. Tri-
umph is very juicy, heavy and
slightly larger than Royal. It
possesses an unusually sweet but
distinctive grapefruit odor and
flavor. Both varieties are seedy.
Marsh. The Marsh is recog-
nized as one of the best commercial
varieties and is probably more ex-

Fig. 5.-Calamondins make beautiful dooryard trees as shown by this picture at
the Citrus Experiment Station.

'-4 p -.
-I... ... I,

tensively propagated than any
other. The fruit is seedless, white
fleshed, and quite juicy. The tree
is vigorous, large and has dense
Red Grapefruit. There are
many varieties of red- and pink-
fleshed grapefruit, some with
seeds, and some without. The
Ruby, or USDA Red, has the deep-
est red flesh and the fewest seeds
of the many varieties.

The lime is valued primarily as
a highly-flavored acid fruit. Its
fresh juice exceeds that of the
lemon in both acid and sugar con-
tent. It is highly aromatic and
prized for various culinary pur-
poses. It makes a delightfully
cooling beverage. The lime tends
to be everbearing, producing fruit
the year round, with peak produc-
tion from May through August.
Key or Mexican Lime. This
variety is grown principally in the
Florida Keys, south of Miami and
along the Gulf coast. However, it
is known to survive in protected
areas in central Florida. The va-
riety is not strongly recommended
because of its lack of cold hardi-
ness and its excessive thorniness;
in addition, it is very susceptible
to anthracnose, a fungus which
attacks both fruit and foliage.
Persian or Tahiti Lime. This
variety is much larger than the
Key. The seedless fruit is oval,
with a smooth, dark green peel.
The pulp is pale green and yields
an abundance of acid juice of ex-

cellent flavor. The Persian lime
is also one of the less cold-hardy
varieties and its success outside
the southern part of the state is
limited to well protected sites.

Florida has many varieties of
lemons but, unfortunately, nearly
all are subject to a gum disease
that seldom kills the tree outright
but reduces it to an unattractive
state. Most lemon trees will pro-
duce an abundance of fruit in spite
of the disease. It is believed this
condition will be corrected through
the budwood certification pro-
gram, but until certified and
disease-free trees are available,
the dooryard grower should expect
some difficulty with practically all
true lemon varieties. Some of the
better strains are the Villafranca,
Avon, Harvey and Eureka.
Meyer Lemon.- Although this
fruit is not a true lemon, it is ap-
parently the most disease-free and
cold-resistant of the lemon group.
It develops into an apparently
healthy, well-shaped tree that
bears large golden fruit with a
very thin smooth peel. The fruit
is practically seedless, with flesh
so tender that it is prized by most

There are several other attrac-
tive and useful varieties of citrus.
Three of the most popular are the
kumquat, calamondin, and lime-
Kumquat.- Possibly the most
widely used of all dooryard citrus,

the kumquat bears small orange-
like fruit 3/4- to 1-inch in diame-
ter. The fruit can be eaten, peel
and all, from the hand, or used to
make marmalade, jellies, candies,
and so on. The trees are small and
can be grown as shrubs, making
excellent ornamentals. Common
varieties are Nagami, Meiwa and
Marumi. Nagami fruit are oblong
to slightly pear-shaped; the others
are round and somewhat sweeter.
Calamondin. This small fruit
is shaped like a tangarine and has
very acid pulp. The tree grows to
a height of 15 to 20 feet, it well-
formed with beautiful foliage, and
bears a very heavy crop of yellow-
to-orange fruit. It is used mainly

as an attractive ornamental, al-
though the fruit can be used as a
substitute for limes and lemons.
Limequat. These hybrids re-
sulted from crossing the lime with
the kumquat. All limequats pro-
duce fruit resembling the lime in
appearance and character. In gen-
eral, they should be considered as
substitutes for that fruit. They
are more hardy than the lime and
probably more resistant to certain
diseases. They can be recommend-
ed for cultivation only as a home
fruit for sections slightly too cold
for the lime. There are several
"named" varieties of the limequat.
Eustis, Lakeland and Tavares are
the most common.

Planting Site

Citrus thrives best in direct sun-
light. Trees planted under even
partial shade will tend to be weak
and unsatisfactory. Practically all
varieties, when budded or grafted
on the more common stocks, are
rapid-growing symmetrical trees,
usually attaining an overall height
and spread of approximately one
foot per year.
In selecting a site, keep this rate
of growth in mind. Spacing is most
important. The distance at which
trees are planted depends upon
variety, soil type, rootstock, and
climatic influence. Each of these
factors has an important effect
upon size of the mature tree.
The spacing for most orange
trees is 25 feet by 25 feet; for
grapefruit it is 25 feet by 30 feet
or 30 feet by 30 feet. Spacing for
most of the mandarin types and

mandarin hybrids, such as the
Temple and tangelo, can be reduced
to a 20-foot square; satsuma, kum-
quat, calamondin and most lime
and lemon varieties require only a
15-foot square. All varieties may
be planted at closer spacings and
hedged to a desired shape or size.
Poorly-drained soils are to be
avoided if at all possible; however,
this can be overcome in part by
special soil preparation such as
bedding or mounding the planting
site prior to planting the tree.
There is one important caution
in selecting a site. Septic tanks and
their drain fields are to be avoided
when planting. Tree roots will clog
the drain, and detergents, soaps,
alkalies, borax and other chemi-
cals used in the home will usually
injure the tree.


Selecting the Tree

Choose the variety and rootstock
that will best suit the site, soil
and area. Purchase trees from ex-
perienced and reliable nurserymen.
Citrus trees are delivered from the
nursery in one of four conditions:
(1) bare-rooted; (2) bare-rooted,
but placed in sphagnum moss, ex-
celsior or some similar material;
(3) balled and bagged (burlap
placed around a small root system
that has been lifted with the soil
still around the roots); and (4) as
potted trees. The latter two meth-
ods are better for the home gar-
dener, as the root system is better
protected and less likely to dry out
before planting. Citrus rootlets dry
quickly when exposed, and once
dry, they cease to function.
Buy either one- or two- year-old
budded trees. Avoid older trees r'g. 6.-A cull tree. The large, hard
stump indicates that the rootstock has
which may be culls unless they been rebudded and is probably diseased.

Fig. 7.-This bare-rooted tree has Fig. 8.-A potted tree is easily trans-

had the top "hatracked" or "buck-
horned" to balance the root system.



have been grown specifically for
dooryard trees. In such instances,
the trees will cost more and re-
quire special attention during and
immediately following planting.
Well-grown one-year-old citrus
buds should be 1/2 to 3/4 inch, and
two-year-old /4 to 11/4 inches in
diameter (usually called caliper)
when measured one inch above the
bud union.
Larger trees may be planted,
but the transplanting requires


The preferred time for planting
is while the tree is most dormant,
usually in late January or Febru-
ary. Normally young trees will go
through several cycles of growth
during the year. If the planting
cannot be made in the early spring
prior to the start of these cycles,
it is well to let the current flush
mature before digging and trans-
planting the tree.
The area where the tree is to be
planted should be spaded and all
roots, vines, sticks and foreign
material removed. The immediate
area should have all lawn sod and
grass removed prior to spading up
an area 4 to 6 feet in diameter;
this area should be leveled with
a steel garden rake.
Dig a hole sufficiently wide and
deep to accommodate the root sys-
tem. This can be judged by plac-
ing the tree in the hole and then
altering the hole to fit the tree.
If the tree is bare-rooted, in-
spect it for broken or damaged
roots. Prune off these with an

skill and knowledge and should be
done only by a thoroughly quali-
fied person.
Good nursery stock will have
large, thrifty leaves and bright,
clean bark. The bud union should
be smooth and at least three inch-
es above the ground level. Avoid
trees with a hard, stunted appear-
ance. The bark on such trees is
usually dark grey, the trunk crook-
ed with definite areas or joints re-
flecting arrested growth (Fig. 10).


Fig. 9.- Removing undesirable and
bruised roots from a good root system.

Fig. 10.-Painting pruning wounds on
larger roots.

Fig. 11.-For spring or summer plant-
ing, the author trims the top of a fresh-
ly dug tree to balance the root system.

Fig. 13.-Half set tree ready to be
watered and have soil firmed around

Fig. 12.-Using a planting board to
establish correct depth of planting.

Fig. 14.-Properly set tree with water
ring ready for future waterings.

%'- I

even, sloping cut. If the root is
larger than 1/2 inch in diameter
paint the cut with a good pruning
If the tree is bagged or potted,
remove the bag or pot completely.
Place the tree gently in position
and throw in a few shovels of soil.
The tree should be set in such a
way that, after the soil has settled,
the tree will be just a little higher
than it was when growing in the
Fill the hole one-third to half
full with soil and settle the soil
in the bottom of the hole by using
several gallons of water. If a gar-
den hose is used, turn it on full
force (no nozzle) to wash the soil
in place and remove all air pock-

ets. Cut off the water; allow that
in the soil to settle, and continue
to fill the hole with soil until it
is two-thirds filled. Repeat the ap-
plication of water; shake the tree
gently and work the watery soil
tightly around the roots. Finish
filling the hole and pack the soil
firmly around the tree. If the dan-
ger of cold weather has not passed,
bank the tree immediately. (See
instructions on banking under
Cold Protection.)
Watering is one of the most im-
portant steps in growing a citrus
tree. Form a watering cup by
mounding the soil 3 to 4 inches
high in a circle around the tree.
The circle should be at least 30
inches in diameter.

Part II--Maintenance of Dooryard Citrus
Care of Non-Bearing Trees

The young tree produces struc-
ture for future fruit bearing and
should be forced to produce as
much vegetative growth as pos-
sible during the first three or four
years. This means careful atten-
tion to watering, fertilizing, culti-
vating and protecting against cold,
insects and diseases.

First Year
Water.- The young tree must
be watered thoroughly and con-
sistently. On dry sandy soils, apply
water three times a week for the
first two weeks after planting.
Heavier soils may require only one
watering per week. For the first
year, the trees should be watered
at least once every week or 10

days during periods of no rainfall.
Fertilization.- Newly-set trees
should not be fertilized until they
show visible signs of growth, usu-
ally from four to six weeks after
they are set. The first application
should be light, not more than 1/.
pound of a 6-6-6 citrus special
containing minor elements. Each
succeeding application, at six-week
intervals, may be increased slight-
ly until the tree is receiving ap-
proximately 1 1/3 pounds on the
last application of the first year.
In areas where trees are subject
to severe winter cold, stop fertili-
zation by mid-August to allow
sufficient time for all new growth
to mature.
Cultivation. Maintain weed

and grass control around the base
of the tree by hoeing a circle two
to six feet in diameter. Mulching
is not recommended for citrus be-
cause it frequently leads to fungus
attacks that seriously damage or
kill the tree. If this form of culti-
vation is used, however, never let
the mulching material come in
contact with the trunk of the tree;
leave a space at least 8 inches in
diameter adjacent to the tree ex-
posed to sunlight and air to reduce
the possibility of fungus attack.
Cold Protection.- When young
trees are planted in northern or
northcentral Florida before the
danger of freezing temperatures
has passed, bank them with soil
that is free of grass, roots and
leaf mold, to a point well above the
bud union. The bank should be
14 to 20 inches high. Remove the
bank as soon as the danger of

freezing has passed. Bank them
each winter (in mid-November)
for the first two or three years,
until the tree has gained some size
and is better able to withstand
freezing temperatures.

Pruning.- Avoid unnecessary
pruning; removing leaves retards
growth and increases the time
required for trees to come into
bearing. To develop a better fruit-
ing structure, remove, while they
are still young and succulent,
sprouts that develop on the trunk
of the tree below the scaffold
limbs. In the case of a straight-
stocked tree, remove the sprouts
that appear below the area to be
branched to form the top of the
tree. Leave the tops unpruned un-
til the tree is bearing or trim only
as is necessary to remove dead

Fig. 15.-Citrus trees make better growth when grass is not permitted to grow
too close to them. The grass takes up much of the plant food.



%; I

Second Year
The program for the second
year should approximate that of
the first, except for watering and
fertilizing. Water second-year
trees thoroughly-10 to 20 gallons
of water per application every
two or three weeks, depending on
weather conditions. In very dry
weather the trees tend to wilt at
mid-day and it will be necessary to
water. If the season is normal very
little additional water will be need-
ed during the second year.
The frequency of fertilization
and the analysis of the fertilizer
may remain the same throughout
the second year, but the amount
per application should be increased.
Begin in the early spring (January
in the southern area, February 1
in the central and February 15 in
the northern) with the same rate
used during the last application
in the preceding fall (about 1 1/3
pounds). Gradually increase the
amount at six-week intervals until
2 1/3 pounds are applied during
the last application in the fall.

Third Year
Normally the tree will be estab-
lished by the third year and little
or no watering will be necessary.
However, during droughts the
trees may tend to wilt badly be-
tween noon and 2:00 p.m. and
should receive 25 to 30 gallons of
water. Sometimes additional ap-
plications will be needed at from
two- to three-week intervals if
drought is prolonged.
Most varieties will bloom in the
third year and may set a few fruit.

This fruit may or may not be left
to mature. Normally, trees of this
age mature only a few fruit of
poor quality and for this reason
the fruit are usually removed.
Fertilization will be the same as
during the second year. Apply 2-
1/3 pounds and increase the
amount each six weeks. By the
last application the amount should
be 4 pounds. As the fertilizer rates
are stepped up, increase the area
of soil on which it is applied. A
good rule of thumb is to begin at
the base of the tree and cover the
soil evenly in a circle out to a
distance of at least two feet be-
yond the drip of the tree.

Fourth Year
The primary concern for the first
three years is to establish a tree
with good vegetative growth. At
the beginning of the fourth year,
however, certain changes are due;
the fertilization schedule should
be reduced to only three or four
applications of 4 pounds each for
the entire year. If dry weather
prevails, water the trees thorough-
ly a day or two before the applica-
tion, and again a day or two after
the fertilizer has been applied.
During the fourth year allow
the tree to mature whatever fruit
it sets. This will not be top quality
fruit but will be acceptable and
the practice will tend to reduce
vegetative growth and promote
fruitfulness in future years.
By the fifth year the tree should
be producing good fruit in

Care of Bearing Trees

Cultural requirements for suc-
cessful fruit production include
fertilization, cultivation, pruning,
irrigation, cold protection, control
of insect pests and diseases and

Citrus will grow under a wide
range of nutritional levels, so it
is impossible to outline any one
program of fertilization which is
better than all others for all
conditions. Size and quality of
the fruit of any one crop in any
given year are not determined
solely by the ratio or poundage of
any single fertilizer application, or
even a single year of fertilization.
They are determined instead by
the condition of a tree, which re-
flects practices for a period of
several years.
Not only fertilization, but also
insect and disease control, irriga-
tion, soil conditions, weather and
other factors exert an influence on
fruit quality.
Ordinary lawn and shrubbery
fertilizers usually contain only the
three primary plant food elements
- nitrogen, phosphorus and potas-
sium. Citrus requires, in addition
to these, magnesium, manganese,
zinc, copper and sometimes boron,
iron and molybdenum for best
growth and fruiting.
For average soil conditions in
Florida the following fertilizer an-
alysis will be generally satisfactory
for dooryard citrus trees:
N P K Mg Mn Cu
6 6 6 4 0.75 0.25

This mixture can be used for all
applications throughout the year.
Make three applications per year,
generally in January or February,
May or June and October or No-
vember. Apply fertilizer to the
entire rooting area, which usually
extends well beyond the drip of
the tree.
The amount of the application is
an important factor. Over-fertili-
zation tends to make the tree ex-
cessively vegetative, with a result-
ing reduction in quality and quan-
tity of fruit. On the other hand,
yellowing or lightness of color
(other than that of immature
growth) is a sign of hunger. To
maintain foliage of a good dark
green color a fairly safe rate in
each application is 2/3 pound of
the 6% nitrogen mixture, per year
of age of the tree, up to 10 years.
After 10 years, 1 pound. A total
of 90 pounds per year will suffice
for trees 30 years old or older.
This recommendation is made
for trees without lawn grasses
growing under them. If the tree
is growing in a sod, 25 to 50 per-
cent additional fertilizer must be
applied to allow for the amount
the grass will absorb. Apply the
fertilizer when grass is dry and
then wash all fertilizer into the
soil to avoid burning the lawn.
Trees growing on alkaline soils
will require at least one nutritional
spray per year. For best results
apply a dormant spray in the early
spring, just before growth starts.
Most garden supply houses carry

nutritional elements already mix-
ed; however, if a spray is not
readily available in prepared form,

Table 1
Basic Copper sulphate or
neutral copper compounds
Zinc sulphate ..
Manganese sulphate
Hydrated lime

mix according to the formula in
Table 1. The following mixture is

3 Gals.

3 Tablespoons
2 /2 Tablespoons
3'/2 Tablespoons
6/2 Tablespoons

It is recommended that soil pH
around citrus trees be maintained
between 5.5 and 6.2. Apply suffi-
cient liming material, such as dolo-
mite or agricultural limestone,
each year to prevent the pH from
dropping below 5.5. This require-
ment can be determined by draw-
ing soil samples from beneath the
drip of the branches and having
them analyzed by your county
agent or other competent author-

Cultivation is not an absolute
essential for successful citrus
growing, but a certain amount of
shallow tillage appears to stimu-
late growth. Cultivation of door-
yard trees with large tools is us-
ually undesirable and imprac-
tical; however, the soil can be well
aerated and tilled with such simple
hand tools as the hoe and rake.
Keep soil free of weeds and lawn
grasses from the trunk of the tree
out to the drip. This practice af-
fords ample cultivation, allows for
satisfactory fertilization and pre-
sents an attractive landscape

Pruning of citrus trees that are
grown for fruit production should
be confined almost entirely to the
removal of dead or broken limbs.
The removal of healthy, well-
developed leaves reduces the abil-
ity of the tree to bear fruit and
should be avoided as much as
In older trees the periodic re-
moval of dead wood is important.
For the sake of appearance and to
facilitate care, remove sprouts
from the tree trunk. Prune out
only enough growth of the center
of the tree to facilitate fruit pick-
ing and the control of insects and
diseases. Most citrus trees at times
will produce long, vigorous sprouts
called suckers. If these suckers or
water sprouts are left alone they
tend to fill the inside and top of
the tree with a tangle of growth
that is susceptible to attack by
disease and insects.
In pruning, make all cuts smooth
leaving no stub or ragged edges.
Remove all twigs or branches at
a fork or branch, if possible; if
not, dress the wound down until
the cut area is flush with an area

of surrounding bark. Treat and
seal all cuts over 1/ inch in di-
ameter with a heavy water-repel-
lent paint. Tree surgical paints
with an asphalt base are prefer-
able. A tree wound should not be
coated with ordinary house paints,
as they are likely to contain min-
eral spirits, solvents or other sub-
stances that will further injure
the bark and prevent healing.
To remove dead twigs, limbs
and decayed areas, always make
the final cut into live healthy wood.
Waterproof the wound and it will
usually callus over.
Citrus trees in some sections
occasionally suffer serious injury
from cold. It is impossible to de-
termine the full extent of a severe
injury at once, since mature trees
may continue to deteriorate for
several months following a freeze.
If only slight damage is caused by
cold, pruning may be done as soon
as new growth indicates the ex-
tent of the injury. However,
since pruning stimulates growth,
it is advisable to withhold all prun-
ing until danger of cold has passed
Where trees have been killed
back to large limbs, no pruning
should be attempted for at least
six months to allow the tree to
recover from the shock and to as-
certain which limbs should be re-

Under Florida conditions it is
seldom necessary to water bearing
dooryard citrus trees. If trees are
located in an area where lawn

sprinklers are operated, such as
an average lawn, it is possible to
damage the tree by too-frequent
applications. Arrange the sprink-
ler system so that areas contain-
ing citrus trees are not watered
more than every other day on well-
drained soils, and less frequently
on poorly-drained soils.

Cold Protection
In spite of Florida's mild sunny
winters, there are times when cold
air comes rolling in to send the
temperatures tumbling. At such
times trees in colder locations
should receive some frost protec-
tion. Young trees (under four
years) should be banked with
clean soil to a height of 14 to 20
In areas likely to have damag-
ing temperatures, curtail spraying,
fertilizing and cultivation by early
September to allow the tree to
"harden-off" for the winter.
The final resort is the commer-
cial grove heater. The "stack-
return"1 type heater is most satis-
factory for home use since it elimi-
nates most of the smoke and soot
and there is no exposed flame. No
heating directions will be ap-
propriate for all conditions. Gen-
erally, Florida cold comes from the
north and northwest; if there are
no buildings or heavy windbreaks
on the side of the citrus to be
protected, a minimum of two heat-
ers for the individual tree will be
required-one on the north, the
other on the west. Where sev-
eral trees are grouped fewer heat-
ers will be necessary.

Fruit Splitting
Each year in September and
October, home-owners and com-
mercial growers report the occur-
rence of split fruit on their orange
trees. Formerly, this condition
caused considerable economic loss
to the Florida citrus industry;
now, although no longer a big
factor in commercial groves, it
still is a matter of concern to many
home growers.
The exact cause of this condi-
tion is not always known, but
there are certain conditions which
are known to cause fruits to split
while still on the tree. This can
and does occur when there is in-
sufficient copper available to the
tree. At one time this was called
In most groves copper deficiency
or ammoniation is no longer a prob-
lem. Actually most Florida bear-
ing-age groves now have an
abundant supply of copper accumu-
lated in the soil. As a matter of
fact, many groves have entirely
too much copper.
The mott common belief is that
fruit splitting results from a
physiological condition. During
;he late summer and early fall

there may be periods of heavy rain-
fall and high humidity mingled
with periods of drought. After a
series of heavy rains, the trees
absorb considerable moisture and
force it into the fruit. Since the
fruit is approaching maturity at
this season, the rind has become
less pliable and fails to expand
rapidly enough to accommodate
the unusually large volume of
liquid being pumped into it by the
Splitting occurs more frequent-
ly in Mediterranean sweet, Valen-
cia and seedling oranges than in
other varieties. The condition is
more common in young trees than
in older, more settled, bearing
trees. It does however, frequently
become a serious problem of older
Since actual cause of the trouble
is not fully understood, there is
no absolute method of control.
Obviously, the condition cannot be
remedied on a current crop. For
future crops, fruit splitting can be
lessened considerably by applica-
tion of fertilizers containing the
necessary minor elements and by
irrigation during periods of

For information on control of insects and diseases of dooryard
citrus trees see Cooperative Extension Service Circulars 137
and 139A. They are available from the offices of county Exten-
sion agents, or from the IFAS Bulletin Room, Building 664,
University of Florida, Gainesville.


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

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of Florida

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