• TABLE OF CONTENTS
HIDE
 Historic note
 Front Cover
 Introduction
 Thatch
 Thatch control
 Lawn renovation
 Back Cover














Group Title: Bulletin - University of Florida. Florida Cooperative Extension Service ; no. 193
Title: A guide to commercial turf renovation in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF90000453/00001
 Material Information
Title: A guide to commercial turf renovation in Florida
Series Title: Bulletin Florida Cooperative Extension Service
Alternate Title: Turf renovation
Physical Description: 8 p. : ill. ; 28 cm.
Language: English
Creator: Meyers, Harry George, 1936-
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla.
Publication Date: [1980?]
 Subjects
Subject: Turfgrasses -- Florida   ( lcsh )
Turf management   ( lcsh )
Lawns -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: Harry Meyers.
General Note: Cover title.
Funding: Bulletin (Florida Cooperative Extension Service)
 Record Information
Bibliographic ID: UF90000453
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000405094
oclc - 10775881
notis - ACF1324
 Related Items
Other version: Alternate version (PALMM)
PALMM Version

Table of Contents
    Historic note
        Historic note
    Front Cover
        Page 1
    Introduction
        Page 1
    Thatch
        Page 1
        Page 2
    Thatch control
        Page 3
        Page 4
    Lawn renovation
        Page 5
        Page 6
        Page 7
        Page 8
    Back Cover
        Back Cover
Full Text





HISTORIC NOTE


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
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida






Bulletin 193


by Harry Me rs
[.F.A.S. U of Fe:
TA I 17.V



p CIA,


Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences / University of Florida / John T. Woeste, Dean











A Guide to Commercial Turf

Renovation in Florida


Harry Meyers

Extension Turf Specialist
University of Florida, Gainesville


INTRODUCTION

The practice of commercial lawn renovation in
Florida has been erratic due to a variety of circums-
tances. Ready availability during the early 1960s of
specialized vertical mowers designed to thin thatch by
removing it, plus potential profit possibilities, pro-
vided incentive for many individuals to enter the com-
mercial lawn renovation business. Interest waned
afterward due to poor results and the necessity for re-
placing turf that often died following renovation.
Another factor having a negative effect on commercial
renovation was the ready availability of inexpensive
builders' sand and topsoil which could be used as a
topdressing to firm up and apparently rejuvenate
excessively thatched turf, thereby eliminating the
need for more costly thatch removal.
Previous renovation failures were due to several
factors:
(1) There was a lack of available information on the
quantity of green vegetation which could be
removed during renovation and still permit full
recovery of remaining turf.
(2) Attempts to renovate excessively thatched and/
or shallow-rooted turf in a single operation
rather than permitting full recovery between
several, less severe renovations, plus consumer
resistance to the cost of several renovations
versus just one, probably motivated commercial
concerns to try accomplishing too much at one
time.
(3) Failure by consumers to irrigate and fertilize pro-
perly following renovation caused additional
damage or death of remaining turf. Unfor-
tunately, most commercial firms had to rely on
customers for proper post-renovation care.
There is renewed interest in turf renovation via


thatch removal. This publication should provide infor-
mation for individuals desiring to enter commercial
turf renovation and for those presently engaged in the
business.
THATCH

What Is Thatch and Why Is It a Problem?
Healthy turf produces vegetation efficiently but if
vegetation decayed as fast as it was synthesized there
should be no accumulation of organic matter. Unfor-
tunately, this does not happen; thus, there is a gradual
buildup of organic matter or plant residue. Thatch is a
naturally occurring surface accumulation of live, dead and
dying stems, stolons, rhizomes, leaves, roots, and their
residues which accumulate in a layer above the soil surface
but below normal mowing height.
Accumulation of thatch occurs as a layer above the soil
surface but distribution of plant parts and organic par-
ticulates are not uniform within the layer. The upper
portion of the thatch layer on warm season grasses
usually consists of a loosely interwoven matrix of live,
dead and dying stems, stolons, leaves, leaf sheaths, and
other plant matter which imparts a sponginess or
springiness to the turf. There is a gradual decrease in
organic matter particulate size from top to bottom of
the thatch layer accompanied by a progressive
increase in the quantity and density of this material to
the soil line (Figure 1). This increase in fineness and
density of organic matter toward the bottom of the
thatch layer is due in part to mechanical and vibratory
effects from mowing and other surface traffic, and
improvement, of conditions necessary for decomposi-
tion. The finely divided organic matter is often peat-
like, not very compressible, and does not add signifi-
cantly to the springy or spongy nature of thatched
turf.


The use of a trade name is solely for the use of providing a specific illustration and is not a guarantee, warranty, or endorsement of the product name,
and does not signify that it is approved to the exclusion of others.











A Guide to Commercial Turf

Renovation in Florida


Harry Meyers

Extension Turf Specialist
University of Florida, Gainesville


INTRODUCTION

The practice of commercial lawn renovation in
Florida has been erratic due to a variety of circums-
tances. Ready availability during the early 1960s of
specialized vertical mowers designed to thin thatch by
removing it, plus potential profit possibilities, pro-
vided incentive for many individuals to enter the com-
mercial lawn renovation business. Interest waned
afterward due to poor results and the necessity for re-
placing turf that often died following renovation.
Another factor having a negative effect on commercial
renovation was the ready availability of inexpensive
builders' sand and topsoil which could be used as a
topdressing to firm up and apparently rejuvenate
excessively thatched turf, thereby eliminating the
need for more costly thatch removal.
Previous renovation failures were due to several
factors:
(1) There was a lack of available information on the
quantity of green vegetation which could be
removed during renovation and still permit full
recovery of remaining turf.
(2) Attempts to renovate excessively thatched and/
or shallow-rooted turf in a single operation
rather than permitting full recovery between
several, less severe renovations, plus consumer
resistance to the cost of several renovations
versus just one, probably motivated commercial
concerns to try accomplishing too much at one
time.
(3) Failure by consumers to irrigate and fertilize pro-
perly following renovation caused additional
damage or death of remaining turf. Unfor-
tunately, most commercial firms had to rely on
customers for proper post-renovation care.
There is renewed interest in turf renovation via


thatch removal. This publication should provide infor-
mation for individuals desiring to enter commercial
turf renovation and for those presently engaged in the
business.
THATCH

What Is Thatch and Why Is It a Problem?
Healthy turf produces vegetation efficiently but if
vegetation decayed as fast as it was synthesized there
should be no accumulation of organic matter. Unfor-
tunately, this does not happen; thus, there is a gradual
buildup of organic matter or plant residue. Thatch is a
naturally occurring surface accumulation of live, dead and
dying stems, stolons, rhizomes, leaves, roots, and their
residues which accumulate in a layer above the soil surface
but below normal mowing height.
Accumulation of thatch occurs as a layer above the soil
surface but distribution of plant parts and organic par-
ticulates are not uniform within the layer. The upper
portion of the thatch layer on warm season grasses
usually consists of a loosely interwoven matrix of live,
dead and dying stems, stolons, leaves, leaf sheaths, and
other plant matter which imparts a sponginess or
springiness to the turf. There is a gradual decrease in
organic matter particulate size from top to bottom of
the thatch layer accompanied by a progressive
increase in the quantity and density of this material to
the soil line (Figure 1). This increase in fineness and
density of organic matter toward the bottom of the
thatch layer is due in part to mechanical and vibratory
effects from mowing and other surface traffic, and
improvement, of conditions necessary for decomposi-
tion. The finely divided organic matter is often peat-
like, not very compressible, and does not add signifi-
cantly to the springy or spongy nature of thatched
turf.


The use of a trade name is solely for the use of providing a specific illustration and is not a guarantee, warranty, or endorsement of the product name,
and does not signify that it is approved to the exclusion of others.

















t1 -.iB&,:, I eL ArkI ',: -- NORMAL MOWING HEIGHT


PHASE I


PHASE II


- SOIL LINE


Figure 1. Cross section of St. Augustinegrass showing thatch layer. Phase I is a loosely
interwoven matrix of live, dead and dying stems, stolons, leaves and leaf
sheaths which imparts a sponginess or springiness to the turf Phase II consists
of finely divided organic matter in advanced states of decomposition. The
quantity and density of this deposition is greatest at the soil line. Phase II is
peat-like, not very compressible, and does not add significantly to the springy or
spongy nature of thatched turf


The upper portion of the thatch layer consisting of loosely
interwoven plant parts is called Phase I thatch, and the
finely divided organic matter which is greatest at the soil
line is Phase II thatch. The entire thatch layer inclusive of
Phase I and II is called thatch.
Excessive Phase I thatch produces a soft, spongy turf
that is difficult to mow uniformly and scalps easily during


mowing, often exposing pale green undergrowth or brown
basal growth. Pale green areas may turn brown before they
recover, or may die depending on scalping severity. Spongy
turf often lacks uniform height, color and appearance
following mowing. Phase II thatch does not contribute sig-
nificantly to the spongy condition of thatched turf but is
capable of holding several hundred times its weight in


THATCH LAYER










water and has a very high cation exchange capacity. These
characteristics enable it to effectively intercept and/or
impede downward movement of air, moisture, pesticides,
and plant nutrients.
Thatch provides ideal breeding grounds for insect and
disease organisms while reducing efficacy of applied
pesticides. Shallow root systems and low drought tolerance
are usually associated with thatch. Thatch becomes
hydrophobic or repels water when dry and is slow and
difficult to re-wet. Excessive thatch makes turf difficult and
costly to maintain, increases low temperature damage, and
results in eventual deterioration of the grass even with the
best of care.

Causes of Thatch Buildup
Thatch buildup has been attributed to numerous
factors. Thatch is basically a residue problem caused
by excessive crop growth without harvest, in which
vegetative production exceeds decay or removal,
resulting in undesirable accumulation. Grasses
depend upon constant regeneration for survival and
the new growth of creeping grasses covers the old,
causing residue accumulation. Shaded plant parts
eventually die, speeding such accumulation.
Excessive nitrogen fertilization produces abundant top
growth and a rapid buildup of Phase I thatch, but also
increases the decomposition rate of Phase II thatch. Low soil
pH can increase Phase II thatch by inhibiting microbial
activity, and thus, decomposition.
Failure to remove clippings during mowing has been
cited as a cause of thatch buildup, but research findings do
not support this concept. Leaves are low in lignin content
and their decomposition is rapid, producing little effect on
Phase II buildup. High lignin content of organic matter can
increase accumulation by blocking entrance of microbes and
preventing decay. Clipping effects on thatch accumulation,
if any, may be due to stimulated growth from their decom-
position rather than direct physical addition.

THATCH CONTROL

Cultural Practices
The most effective means for thatch control are a com-
bination of management practices designed to reduce the
buildup rate by reducing growth and increasing microbial
decomposition, and by periodic physical removal by scalp-
ing and/or vertical mowing. Scalping and vertical mow-
ing will be discussed under Mechanical Thatch
Removal. Cultural practices include judicious fertilizer
use, soil pH control, soil aerification, and topdressing
with soil.
Fertilizer should be applied as necessary to maintain
reasonable appearance, color, growth, and a dense sod to


minimize weed invasion. Fertilization solely to maintain a
dark green color at all times should be avoided unless color
and appearance are of paramount importance. This is the
situation on a golf green where continual high fertilization
hastens thatch buildup and increases insect and disease
problems. A soil pH of 6.5-7.0 is ideal for maximum
microbial activity and decomposition. Printed information
regarding soil pH control, and suggested fertilization
schedules for various grasses, are available from local
county agricultural extension offices.
Periodic soil aerification and/or light topdressings with
soil are standard maintenance practices on golf courses.
Both practices reduce thatch buildup, but their practical use
is often limited to golf courses due to the cost of specialized
equipment, topsoil and labor. Mechanical soil aerification
aids in penetration of air, moisture, fertilizer and pesticides.
Topdressing increases decomposition by bringing soil
microbes and moisture into contact with the organic matter
comprising thatch.
Thick applications of soil topdressings are not recom-
mended and do not substitute for vertical mowing. The best
solution where a thick layer of thatch has developed is
physical removal by vertical mowing. A thick layer of
topdressing immediately firms spongy turf and produces the
appearance of complete rejuvenation within a few weeks.
Benefits of thick soil topdressings are fleeting since resul-
tant layering complicates future maintenance, by impeding
downward movement of air, water, and nutrients, and
by encouraging shallow root systems.

Mechanical Thatch Removal
Scalping Close mowing or scalping is a procedure in
which turf is mowed at a much lower height than normal.
Scalping can effectively remove large quantities of Phase I
thatch, and depending upon turf type, limited quantities of
Phase II thatch. Scalping is not a substitute for vertical
mowing, but its periodic use helps to firm spongy turf and
delay the need for vertical mowing where Phase II buildup
is minimal.
Methods by which grasses spread, i.e. stolons, rhizomes or
both, determines how severely the grass can be scalped
without its thinning out or dying afterward. Rhizomes are
modified stems that grow horizontally at or below ground
level and help to develop new topgrowth for re-establish-
ment following scalping (Figure 2).
Bahia, bermuda and zoysia grasses are rhizomatous and
may be scalped to the point of removing most green vegeta-
tion and exposing brown basal growth without killing the
turf. In such instances, a portion of Phase II thatch may be
removed during scalping.
Centipede and St. Augustine grasses spread by means of
above-ground stolons or runners. Removal of all live runners
during scalping will kill these grasses since they have no
underground rhizomes. The equipment operator must deter-























- SOIL LINE


Figure 2. Bermudagrass plant with stolons and rhizome.


mine how severely a particular turf type in a specific situa-
tion can be scalped without permanent injury. Determining
severity of scalping for centipede and St. Augustine grasses
is more critical when they are to be vertically mowed after-
ward.
Vertical Mowing Vertical mowers, specialized equip-
ment having evenly spaced, knife-like blades revolving per-
pendicular to the turf, are used to slice and thin thatch by
removal (Figure 3). Depth of penetration is adjustable and
can be set to include soil penetration for partial soil aerifica-
tion. Intensity of thatch removal is governed by blade thick-
ness, spacing, RPM, depth setting, and equipment ground
speed. Thatch removal normally increases with blade thick-
ness, and as blade spacing is decreased. Thatch removal also
increases as depth of cut increases, until soil penetration
occurs.
Grasses should be vertically mowed twice during renova-
tion for best results, the second time at right angles to the
first. As with scalping, the equipment operator must deter-
mine when to stop vertical mowing if the grass has to be
vertically mowed more than twice to remove excess thatch.
Suggested vertical mower blade spacings are given in Table
1. These spacings are based on internode lengths of the
grasses and presence or absence-of rhizomes. Spacings may
be varied from these suggestions but not unless the operator
is thoroughly familiar with the grass and vertical mowing.


When to Vertical Mow The best time to vertical
mow grasses south of Orlando is March through May,
and north of Orlando, April through early June.
Growth during these periods is not as rapid as during
mid-June, July, and early August, but temperatures
are cooler and water requirements less during the
recovery period following renovation. Grasses ver-
tically mowed during the summer not only require
more water due to more rapid growth, but dead organic
matter exposed during vertical mowing can dry
rapidly, become hydrophobic, and complicate proper
irrigation. Under such circumstances, recovery from
vertical mowing can be slowed and/or the grass
severely damaged. These factors are important to com-
mercial concerns since most must rely on customers
for proper irrigation following vertical mowing.

Power Rake This specialized machine uses evenly-
spaced, flexible, spring steel wires that revolve at high speed
to glean through turf and loosen debris for subsequent
removal (Figure 4). The machine and procedure are often
confused with a vertical mower and vertical mowing;
however, there is little cutting action involved. Power rak-
ing is useful for loosening debris in bahiagrasses because of
their open and semi-erect growth, but is of limited value on
other grass types unless preceded by vertical mowing.


.~.:'RHIZOME










LAWN RENOVATION


Assessment
A careful examination of the turf to be renovated is
the single most important step prior to making the
decision to renovate. Items to check include turf type;
turf quality in terms of density, color, and weed
infestation; thatch thickness; and root system depth
and density. Careful examination of these factors does
not take long and provides the basis for recommenda-
tions and of permissible renovation.
Grass Type Bahia, bermuda and zoysia grasses ver-
tically mowed in two directions require approximately 30
days for full recovery during the growing season, whereas
St. Augustine and centipede grasses may require 30-90
days.
Turf Quality The turf quality aspect of evaluation is
important in determining the degree of renovation to
attempt. Overall turf appearance is also indicative of
customer interest and the type of care the turf will receive
following renovation. Turf that is excessively spongy but
has fairly good color and density, and minimal weed con-
tamination, is healthier and can be more severely renovated
than turf that has deteriorated to the point where it has
become thin and weed-infested.
Thatch Thickness and Root Quality These factors
are usually evaluated jointly since thatch thickness indi-
cates the quantity of organic matter which should be
removed, while root system quality usually dictates the
extent of permissible renovation.
The first step in root system evaluation is to grab a
handful of turf and vigorously attempt to pull it out of
the soil. Sparse or shallow-rooted turf is easily pulled
out of the soil, much like a piece of carpeting. Poorly-
rooted turf may be due to one or more of the following:
poor management practices, excessive thatch, poor soil
topdressing practices, and/or nematodes.
Vertical mowing 'poorly-rooted turf in a weakened con-
dition is not advised since the mechanical slicing action may
loosen and strip the turf from the soil in patches and/or
further weaken it, causing death following renovation.
Options for such a situation include:
(1) Resodding Virtually any turf can be renovated
regardless of its condition, provided time, effort, and
expense are no object. Economic practicality takes pre-
cedence when cost for proper renovation exceeds that
for resodding. Resodding should be recommended
when careful evaluation indicates it to be less expen-
sive than renovation. No one enjoys refusing business,
but shortcuts taken to keep cost within reason often
result in unsatisfactory renovation and possible death
of the turf. Not much salesmanship is required to close
a deal when renovation is offered as a less expensive


substitute for resodding. The ultimate question is: can
the firm deliver afterward?
(2) Scalping Poorly rooted turf often may be safely
scalped provided it receives proper care afterward.
Subsequent management practices, including applica-
tion of an approved nematicide when applicable,
should be designed to encourage deep rooting prior to
vertical mowing. Scalping prior to application of an
approved nematicide usually is best since excess
organic matter can substantially reduce efficacy of
applied pesticides.
One method for examining thatch thickness and root
quality is to use a a straight-bladed garden spade to remove
an intact, 4x8-inch cross section of turf with approximately
6 inches of attached soil. Overall thatch thickness should be
carefully examined, especially on St. Augustine and cen-
tipede grasses, to determine the quantity or thickness of
Phase I thatch and finer Phase II thatch. The preceding
thatch profile examination should provide a rough quantita-
tive estimate of how much Phase I thatch can be scalped off
prior to vertical mowing and still insure adequate green
vegetation for re-establishment afterward.
Thatch profile examination can also reveal, to a certain
degree, past maintenance practices which can have a
modifying effect on the best or most practical method for
renovation. For example, very little dead Phase I and II
thatch in relation to a relatively thick layer of green Phase I
thatch indicates rapid buildup over a short time span, proba-
bly from excessive fertilization. Scalping combined with
reduced fertilization may be all that is required to effec-
tively renovate the turf in this situation.
Final examination of the thatch/soil sample consists of
determining root depth and density.
Depending upon original thickness, previous applications
of soil topdressing may occur in sample cross sections as
alternating layers of soil and buried organic matter. One
should gently attempt to pull the sample apart while grasp-
ing the lowermost soil portion in one hand and pulling on
the thatch layer with the other hand. A reasonably clean
separation at any of the layers indicates the effective root-
ing depth. Carefully shake or wash soil and/or organic mat-
ter from sample to expose roots and their density. If the
sample does not separate at any of the layers, then carefully
shake and/or wash the entire sample to expose root systems.
There are no quantitative guidelines for root system
evaluation relative to vertical mowing, but successful
renovation becomes more difficult as root system depth and
density decreases. A majority of the root system should
extend a minimum of 2 or more inches into the underlying
native soil.

Equipment Requirements
The following list is intended to serve as an equipment











guide for residential lawns and small commercial turf areas
such as motels, hotels and condominiums. Requirements for
larger turf areas differ in that larger, high-speed equipment
is required.


Quantity Description


Heavy duty, self-
propelled, vertical
mower, 10-12 HP.


Medium duty,
self-propelled,
vertical mower,
4-7 HP.

Heavy duty, self-
propelled, walk-
behind or riding
rotary mower
with catcher.
Mowing swath,
HP, etc. to be
determined
primarily by size
of areas normally
selected for
renovation.

Medium duty,
self-propelled,
walk-behind
rotary mower
with catcher.
Self-propelled,
walk-behind, or
trailing brush-
type sweeper.
Self-propelled,
walk-behind
vacuum sweeper.
/2-1 ton pickup
with high sides.




Utility trailer
with sides.
Miscellaneous
hand tools e.g.
rakes, trash
forks, brooms, etc.


Intended Use

Straight-line
vertical mowing
in open, readily
assessible areas.
Close work around
flower beds and
other tight areas.


Scalping and
clipping removal
prior to and
following vertical
mowing. Essentially
for use in open,
readily assessible
areas.





Scalping and
cleanup work
around flower
beds and other
tight areas.
Debris removal
following
vertical mowing.


Final cleanup and
for removal of fine
Phase II thatch.

Equipment and
personnel transport.
Haul away
debris removed
during renovation.
Equipment transport
and debris removal.


Vertical mower. Unit above in position to vertical mow. Same
unit below tilted upward to expose evenly-spaced steel blades
beneath engine deck.


1t~


Procedure
Flagging Locate and mark irrigation heads, electrical
outlets and other obstructions that may damage or be
damaged by equipment during renovation. Standard irriga-
tion marker flags are excellent for this purpose. Remove
concrete doughnuts or rings used to protect irrigation heads
during regular mowing. Check with the customer to insure
that all irrigation and electrical lines are sufficiently deep to
avoid damage to or by equipment, or injury to personnel
during renovation.
Scalp Adjust mower cutting height as low as compati-
ble for the mower, or for the turf being renovated. A grass
catcher, a walk-behind, or a trailing brush-type sweeper
should be used to remove the majority of clippings prior to
vertical mowing.
Vertical Mow Consult Table 1 for recommended blade
spacing. Changing blade spacings and/or reels is a difficult


;

:


:~-- -~-r-














d~-


Figure 4. Power rake. Unit on left in position to power rake. Same unit on right tilted upward to
expose evenly spaced spring steel wires beneath engine deck.


operation and is usually performed prior to the delivery of
equipment to job sites. Blade spacings listed in Table 1 are
adequate for most situations, but experience may dictate
changes for optimal performance.
The most practical method for determining proper verti-
cal mower blade depth is to make a series of downward
adjustments interspersed with short test runs to determine
the degree of thatch removal. Usually three to four adjust-
ments, each followed by a 5-to-10 foot test run, are sufficient
to determine the best depth setting. The equipment operator
should keep in mind that additional green vegetation will be
removed when the area is vertically mowed a second time at
right angles to the first mowing. A heavy duty mower
usually is best for areas reasonably free from obstructions
thus permitting straight line mowing, while a light-weight,
highly maneuverable unit is more suitable for restricted
areas.
Thatch or debris brought to the surface as a result of ver-
tical mowing should be removed each time the area is ver-
tically mowed to reduce equipment flotation and drag on
subsequent cuts. Failure to remove debris increases power
requirements necessitated by having to re-cut debris.
Final Scalp The area should be re-scalped after final
vertical mowing and cleanup, at the same height as initially
scalped, to produce a uniform height of cut and a neat
appearance.
Vacuum Sweep The final step in thatch removal is to
vacuum sweep the entire area to remove remaining debris
and as much fine or powdery Phase II thatch as possible.
Final scalp and vacuum sweep operations often are reversed
since vacuum sweeping has a tendency to produce a slightly
irregular surface.


Table 1. Recommended
spacings.


Grass Type
Bahiagrass
Bermudagrass
Centipedegrass
St. Augustinegrass
Zoysiagrass


vertical mower blade


Inches Centimeters
1.0 2.54
1.0 2.54
1.0-1.5 2.54-3.81
2.0-3.0 5.08-7.62
1.0 2.54


Topdressing Topdressing to level renovated areas or
fill small depressions may be desirable following final
cleanup. Topdress with soil similar to the native soil on
which the turf is growing and use as little as possible to
minimize layering. Never bury turf with topsoil when level-
ing or filling depressions since this will kill it. Sterilized top-
soil should be used to prevent weed seed germination and
should be screened to remove foreign material such as small
twigs and rocks. Table 2 contains volumes of topsoil
required for varying thickness of topdressing.
Fertilization Renovation by vertical mowing is a tem-
porary setback to actively growing turf, reducing its ability
to synthesize plant food due to removal of green grass
blades. Recovery is more rapid if the turf is properly fer-
tilized immediately following renovation. A 16-4-8 fertilizer
is one of the best ratios, but any fertilizer is usually better
than none. Fertilizers should be applied at the rate of 1.0 lb
(454 gm) of actual nitrogen per 1000 square feet (93 square
meters) and watered in immediately following application.
To determine pounds of fertilizer required to give 1.0 lb (454
gm) of actual nitrogen, divide 100 by the percentage of












nitrogen in the fertilizer (the first number of the fertilizer
analysis). For example, apply 6.25 pounds (2.8 kgm) of 16-4-
8 fertilizer per 1000 square feet (93 square meters).

Table 2. Volumes of topsoil required for top-
dressing 1,000 square feet (93 square
meters) of turf area.


Topdressing Thickness
Inches Centimeters


1/8
1/4
5/16
3/8
1/2
5/8
3/4
1.0


0.32
0.64
0.79
0.95
1.27
1.59
1.91
2.54


Cubic Volume
Feet Yards Meters
10.42 0.39 0.29


20.83
26.04
31.25


0.77 0.59
0.96 0.74
1.16 0.88


41.67 1.54 1.18
52.08 1.93 1.47
62.50 2.31 1.77
83.30 3.09 2.36


Post-Renovation Care

Except for irrigation, normal maintenance practices
including mowing and insect and disease control


should be resumed immediately following renovation.
Dead organic matter exposed in renovated areas dries
quickly, becomes hydrophobic and further stresses
renovated turf which is weakened and less able to
withstand water stress. Thus, renovated turf should be
treated as a new installation and irrigated 2-3 times
daily until the turf is capable of surviving with less
frequent, but deeper watering.
A good irrigation policy is to syringe lightly once or twice
during the day followed by heavier irrigation in the evening.
One-tenth inch (0.25 cm) of water or 62 gallons (235 liters)
per 1000 square feet (93 square meters) applied at 10:00
a.m. and again at 2:00 p.m. should suffice to keep organic
matter moist and in condition to receive the 0.3-0.5 inches
(0.76-1.27 cm) of water recommended for evening irrigation.
The preceding water quantities should suffice under most
conditions, but might require adjustment to better fit all
local conditions.
Daytime syringing should be discontinued as soon as the
turf becomes sufficiently re-established to withstand night-
time watering only. Nighttime irrigation frequency and
quantity should then be adjusted to avoid daytime wilting.
Irrigate during the evening hours on an as-needed basis as
soon as the renovated turf has been fully re-established.


Cover art and Figures 1 and 2 by Lynda Chandler.













































































This publication was printed at a cost of $1,775 or 59 cents per copy, to inform commercial lawn maintenance
personnel about turf renovation practices. 7-3m-80



COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL
SCIENCES, K. R. Tefertiller, director, in cooperation with the United States Department of Agriculture, publishes this Infor-
mation to further the purpose of the May 8 and June 30, 1914 Acts of Congress; and is authorized to provide research, educa- IpAB
tional information and other services only to Individuals and Institutions that function without regard to race, color, sex or
national origin. Single copies of Extension publications (excluding 4-H and Youth publications) are available free to Florida
residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers is available from
C. M. Hlnton, Publications Distribution Center, IFAS Building 664, University of Florida, Gainesvllle, Florida 32611. Before Iuolicizing thisS
publication, editors should contact this address to determine availability.




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