Maintenance of St. Augustinegrass Lawns1
L. B. McCarty and John L. Cisar2
ESTABLISHMENT
St. Augustinegrass
is established by vegetative propagation because its seeds have poor germination and do not remain true to type. St. Augustinegrass is a stoloniferous grass (with aboveground stems) and can be planted by
sod
,
sprigs
, or
plugs
(Table 1
). Each of these methods can be equally successful if the site is properly prepared and maintained before and after planting.
|
|
St. Augustinegrass. |
|
|
sod. |
|
|
sprigs. |
|
|
plugs. |
New home or building sites should be rough graded. Rocks, roots, and other debris need to be removed. On existing sites, unwanted vegetation should be removed by a nonselective herbicide such as glyphosate (Roundup). A soil test should be taken in the area to determine the pH and the need for plant nutrients. These nutrients need to be applied before planting, and tilled in if the soil is bare. The next step is the installation of a new irrigation system, or repairs to an existing system. Before any grass is planted, the area should be final graded and thoroughly moistened to help the establishment process.
The best time to plant St. Augustinegrass is during active growth, normally April through July. Other times may be suitable, with sufficient care to prevent desiccation and cold damage. The chapters entitled "Preparing to Plant a Florida Lawn
" and "Establishing Your Florida Lawn
" in this publication give additional details on turf establishment.
Sodding
Establishment of St. Augustinegrass by sodding produces an instant lawn.
Sod
should only be laid over bare, moist soil, with pieces laid in a staggered, brick-like pattern and the edges fitted tightly together to avoid cracks. Often, sod is placed over existing turf. This generally produces a lower quality turf and should be avoided. Fill any cracks between strips with soil to avoid open spaces for weed encroachment. Rolling and thorough watering will ensure good contact with the soil for fast rooting. Newly sodded areas should be watered at least twice daily with ¼ inch of water until the sod is held fast to the soil by roots, then watering (¾ inch) should be reduced to an as-needed basis (e.g. when the turf wilts).
|
|
Sod. |
Sprigging
Planting St. Augustinegrass by sprigging is an effective way to patch small areas of turf but is too labor-intensive for large areas unless it is performed mechanically. Fresh
sprigs
are stolons (runners) that have at least two nodes or joints. These are planted
end to end
in rows 6-12 inches apart. The runner should be covered with soil, leaving the leaves exposed. Tamping the soil and a thorough watering help establish the plants. The soil should be kept moist until new stolons are produced.
|
|
sprigs. |
Plugging
A number of the new varieties of St. Augustinegrasses are available commercially as plugs. Sod also can be made into plugs by cutting it into small squares.
Spacing of plugs
varies from 6 to 24 inches. The closer spacing provides full coverage in 3-6 months and farther spacing covers in 6 to 12 months. Plugs are placed in holes of the same size or in open furrows and tamped into place. A thorough watering completes the installation. The turf should then be cared for like a sprigged lawn.
|
|
Spacing of plugs. |
MOWING
Proper mowing practices are important in maintaining an attractive lawn. Both height and frequency of cut need to be adjusted for the level of turf management (Table 1
). Under high levels of management, St. Augustinegrass can be maintained at 2 inches if the lawn is mowed at least weekly during the growing season. Mowing at this height and frequency requires more fertilizer and water to maintain an attractive lawn. Also, low cutting heights and high maintenance levels can predispose the turf to many pest problems. Under moderate or low levels of management, St. Augustinegrass should be cut at a height of 3 to 4 inches. To obtain this height with most home
rotary lawn mowers
, the highest wheel height setting should be used. This height will help the grass develop a deep root system and give a better appearance to the turf. Mowing frequency under moderate or low management should be adjusted to the amount of growth. No more than
one-third the height
of the leaf blades should be removed with any mowing. During periods of moisture stress, or if the grass is growing in shade, increase the mowing height to 4 inches. Newer semi-dwarf varieties have a lower growth habit, and should be mowed at 1½ to 2 inches for optimum quality.
|
|
rotary lawn mowers. |
|
|
one-third the height. |
Mowing too infrequently and improper watering can cause a
thatch
buildup. The secret to mowing St. Augustinegrass at 3 inches is to water the lawn only when there are signs of moisture stress. This will keep growth to a minimum and reduce the rate of thatch accumulation. The chapter entitled "Thatch and its Control in Florida Lawns
" in this publication has more information on thatch.
|
|
thatch. |
Mowing too low can also cause problems in turf quality. Constant low mowing reduces the density and vigor of St. Augustinegrass. Weed problems in St. Augustinegrass lawns can usually be attributed to a low height of cut and improper watering.
Either a
rotary
or
reel
mower can be used on St. Augustinegrass. It is important to keep the blades sharp and well-adjusted to get a clean cut. Dull blades will give the lawn a brownish cast, because a ragged cut shreds the leaf blades rather than cutting them. During the growing season blades should be sharpened on a monthly basis.
|
|
reel. |
Grass clippings can be left on a lawn that is mowed at the proper height and frequency. Under these conditions, clippings do not contribute to the thatch layer. Clippings should be left on lawns maintained with low to moderate fertility levels to help recycle nutrients. Remove clippings if the amount is excessive (e.g., clumping occurs).
WATERING
The best way to irrigate an established lawn is on an as-needed basis. Grass blades will begin to wilt (e.g., fold, turn bluish-green in color and not recover from traffic or footprinting) as the moisture begins to be depleted in the soil. If 30 to 50% of the lawn shows signs of slight wilting, it is time to irrigate with ¾ inch of water. The turf will fully recover within 24 hours. The turf should not be watered again until it shows signs of wilting. This irrigation schedule works for any soil type and environmental condition. For further information on recommended watering practices see the chapter in this publication entitled "Watering Your Florida Lawn
." Proper watering practices will help maintain a lawn that requires less mowing and has little thatch buildup. Proper watering will also help develop a deep root system and encourage plants which are less susceptible to damage by pest and environmental stresses. If the diseases brown patch or gray leaf spot are a continuous problem, overwatering and excessive nitrogen fertilization may be responsible. Certain weeds (like
pennywort
and
nutsedge
) also thrive in soils which are continuously wet. Regulate these management practices closely to reduce disease and weed severity.
|
|
pennywort. |
|
|
nutsedge. |
FERTILIZING
Maintaining a good quality lawn requires a properly planned fertility program. An acceptable quality St. Augustinegrass lawn can be grown with a low to a high level of fertility, depending on what the homeowner wants. First, decide how much time and effort can be spent on lawn maintenance. A low fertility lawn is best for those with little time to spend on lawn care. A high fertility lawn may be better suited to those who find a low fertility St. Augustinegrass lawn unattractive, and have more time for lawn care.
A low-maintenance St. Augustinegrass lawn should be fertilized twice a year, once in the spring and again in the late summer while the grass is actively growing (Table 2
). Apply a complete fertilizer such as 1648, 101010, or 666 with micronutrients at the rate of 1 pound of actual nitrogen per 1000 square feet per application. It is best to leave the clippings on these lawns to recycle nutrients.
At the optimum maintenance level, a St. Augustinegrass lawn should receive 4 pounds of nitrogen per 1000 square feet per year. Apply fertilizer four times per year, in March, May, July, and September, at the rate of 1 pound of actual nitrogen per 1000 square feet. Never apply more than 1 pound of actual nitrogen per 1000 square feet at any one time. A complete fertilizer can be used at every fertilization, although two applications per year is sufficient. A slow-release, nitrogen-only fertilizer may be applied in between complete fertilizer applications. This fertility level, combined with the proper watering practices, will result in a good quality lawn with minimal thatch buildup.
Heavy fertilization rates will produce a faster buildup of thatch than lower rates. High rates of fertilizing can also encourage insect damage to the turf. Additionally, the necessary amount of mowing and watering increases with the amount of fertilizer. Careful planning is necessary to grow the desired type of lawn. The chapter entitled "Understanding Soil Analysis and Fertilization
" provides details on fertilizing turfgrasses in north and south Florida.
PEST PROBLEMS
Several pest problems can affect St. Augustinegrass. Diagnosis and recommendations for treatment of pest problems are available from your county Cooperative Extension Service.
Insects
The major pest of St. Augustinegrass is
chinch bugs
. Large populations of this insect have become resistant to organophosphate insecticides. Alternative chemicals are available, but the best solution is to plant Floratam or Floralawn, since these cultivars are resistant to chinch bugs. Other insect pests, including
webworms
,
armyworms
,
grass loopers
and
mole crickets
, can cause damage on St. Augustinegrass. High levels of nitrogen fertilizer encourage insect problems. Refer to the chapters on specific insect pests for descriptions and information about their control.
|
|
chinch bugs. |
|
|
webworms. |
|
|
armyworms. |
|
|
grass loopers. |
|
|
mole crickets. |
Diseases
Brown patch
and
gray leaf spot
are the two major disease problems of St. Augustinegrass. Brown patch occurs in warm, humid weather and is encouraged by excessive nitrogen. Brown patch is generally most noticeable during spring and fall months. Gray leaf spot occurs during the summer rainy season and is primarily a problem on new growth. Both diseases can be controlled with fungicides. Refer to the section on disease problems for additional information.
|
|
Brown patch. |
|
|
gray leaf spot. |
Nematodes
Several types of nematodes infest St. Augustinegrass lawns. Nematodes cause yellowing and general thinning of older lawns. Refer to the section on nematodes or contact your county Cooperative Extension Service for additional information.
Weeds
Weed problems in a lawn indicate that the turf has been weakened by improper management practices or damage from pests. Proper management practices can eliminate most weed problems. If weeds are a persistent problem, herbicides labelled specifically for St. Augustinegrass should be used. Many commercial weed and feed formulations will provide control, but they should not be used every time the lawn is fertilized. Read and follow any pesticide label before use. The chapter entitled "Weed Control Guide for Florida Lawns
" gives specific weed control recommendations.
Other Problems
Many other factors can decrease the quality of a lawn. To insure a good St. Augustinegrass lawn, refer to other sections of this publication for recommended management practices, and follow label directions when applying fertilizers and pesticides.
Tables
Table 1.
Table 1. Relative growth characteristics for St. Augustinegrass cultivars.
|
|
Normal Growth Habit Cultivars
|
Semi-dwarf Growth Habit Cultivars
|
Characteristics
|
Common/Roselawn
|
Bitterblue
|
Raleigh
|
Floratine
|
Floratam
|
Floralawn
|
FX-10
|
Delmar
|
Jade
|
Seville
|
Mowing Ht. (in)
|
3-4
|
3-4
|
3-4
|
2-3
|
3-4
|
3-4
|
3-4
|
1.5-2
|
1.5-2
|
2-2.5
|
Cold Tolerance
|
poor
|
good
|
very good
|
fair
|
poor
|
poor
|
poor
|
very good
|
good
|
good
|
Shade Tolerance
|
poor
|
very good
|
good
|
fair
|
poor
|
poor
|
poor
|
good
|
good
|
very good
|
Chinch Bug Resistance
|
poor
|
slight
|
poor
|
slight
|
good*
|
good*
|
good
|
poor
|
poor
|
slight
|
Green Color
|
light
|
dark
|
medium
|
dark
|
dark
|
dark
|
medium
|
dark
|
dark
|
dark
|
Texture
|
coarse
|
coarse
|
coarse
|
coarse
|
v. coarse
|
v. coarse
|
coarse
|
fine
|
v. fine
|
fine
|
Density
|
poor
|
good
|
good
|
good
|
good
|
good
|
good
|
good
|
good
|
good
|
*Isolated evidence of a new chinch bug which can feed on these cultivars has been reported.
|
Table 2.
Table 2. Suggested fertilization schedule for St. Augustinegrass lawns.
|
Fertility level
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
June
|
July
|
Aug
|
Sept
|
Oct
|
Nov
|
Dec
|
North Florida1
|
High
|
--
|
--
|
C2
|
--
|
N3
|
Fe4
|
N
|
--
|
C
|
--
|
--
|
--
|
Low
|
--
|
--
|
C
|
--
|
--
|
Fe
|
--
|
--
|
C
|
--
|
--
|
--
|
South Florida1
|
High
|
--
|
C
|
--
|
--
|
N3
|
Fe
|
N
|
--
|
--
|
C
|
--
|
N
|
Low
|
--
|
C
|
--
|
--
|
N3
|
Fe
|
--
|
--
|
--
|
C
|
--
|
--
|
1The arbitrary dividing line between north and south Florida is a straight east-west line from coast to coast through Orlando.
|
2Complete fertilizer at 1.0 lb of nitrogen/1000 sq ft.
|
3Slow release nitrogen fertilizer sources should be used to prevent an excess of succulent growth during chinch bug season. Apply 1.0 lb of nitrogen/1000 sq ft as activated sewage sludge, urea formaldehyde, sulfur-coated urea, IBDU, resin-coated material or other slow-release source.
|
4Iron (Fe) may be applied in summer to provide dark green color without stimulating excessive grass growth. Ferrous sulfate (2 oz in 3 to 5 gal. water per 1000 sq ft) or a chelated iron source may be used.
|
Footnotes
1.
This document is Fact Sheet ENH-5(b), a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. This information is included in the Florida Lawn Handbook, SP-45. For a copy of this handbook, request information on its purchase at your county extension office. First published: May 1991. Revised: January 1995.
2.
L. B. McCarty, associate professor, Commercial Turf Specialist, Environmental Horticulture Department, Gainesville; John L. Cisar, associate professor, Turf Specialist, Ft. Lauderdale Research and Education Center, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.
The term "plates," where used in this document, refers to color photographs that can be displayed on screen from CD-ROM. These photographs are not included in the printed document.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal
Opportunity Institution authorized to provide research, educational
information and other services only to individuals and institutions
that function with non-discrimination with respect to race, creed,
color, religion, age, disability, sex, sexual orientation, marital
status, national origin, political opinions or affiliations.
For more information on obtaining other extension publications,
contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service,
University of Florida, IFAS, Florida A. & M. University Cooperative
Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
Copyright Information
This document is copyrighted by the University of Florida, Institute of Food and Agricultural
Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions,
but permits free reproduction by all agents and offices of the Cooperative Extension Service and the
people of the State of Florida. Permission is granted to others to use these materials in part or in full
for educational purposes, provided that full credit is given to the UF/IFAS, citing
the publication, its source, and date of publication.
