Spring Hill Lawn and Landscape

St. Augustine grass for Florida Lawns

L.E. Trenholm, J.L. Cisar, and J. Bryan Unruh²

St. Augustine /Floratam  grass   widely adapted to the warm, humid (subtropical) regions of the world.

 It is believed to be native to the coastal regions of both the Gulf of Mexico and the Mediterranean. 

 In Florida, St. Augustine /Floratam grass is the most commonly used lawngrass throughout the state.

It can grow satisfactorily in a wide variety of soils.

 

St. Augustine/Floratam grass.

Advantages

St. Augustine produces a green to blue-green dense turf that is well adapted to

most soils and climatic regions in Florida. It has relatively good salt tolerance and

certain cultivars possess good shade tolerance. Establishment of St. Augustine grass

from sod is quick and easy. There are several cultivars commercially available.

Disadvantages

St. Augustine /Floratam grass, like most turf grasses, has certain cultural and pest problems.

It does not remain green during drought conditions without supplemental irrigation.

It produces thatch under high fertilization and irrigation regimes.

It has poor wear tolerance and will generally not stay

green throughout the winter months in many parts of the state.

The coarse leaf texture of most cultivars is objectionable to some people.

The major insect pest of St. Augustine grass is the chinch bug,

There are currently no chinch bug resistant cultivars available.

Grubs can also be a major insect pest. Some cultivars are also susceptible to

diseases such as gray leaf spot, brown patch, take-all patch, and root rot.

Additionally, there are no herbicides available to control hard-to-kill grass-type

 weeds that may become established in the turf.

'Floratam' is an improved St. Augustinegrass that was released jointly in 1973 by the University of Florida

and Texas A & M. 'Floratam' is the most widely produced and used St. Augustine grass in Florida.

It is a coarse-textured cultivar that has poor cold and shade tolerance relative to other St. Augustine grass cultivars.

 It will not persist well in environments that receive less than 6 hours of sunlight daily. It grows

vigorously in warm weather, but has a relatively long period of dormancy in north Florida and greens up

more slowly in the spring than some cultivars. When first released, it had UF-documented chinch bug resistance,

 although that has largely been lost over time and chinch bugs are now a major pest of 'Floratam'.

 It is also susceptible to gray leaf spot and other diseases. 'Floratam' is intolerant of atrazine herbicides

 when temperatures are above 85°F. It is a “standard” cultivar and should be mowed at 3.5 to 4 inches.

'Floratam' is available as a certified cultivar.

'Floratam' in the landscape. This is the most commonly used lawngrass in Florida.

Maintenance of St. Augustinegrass

Proper lawn maintenance practices are the best means for avoiding pest problems and obtaining a

 high-quality lawn. St. Augustine grass will require inputs of fertilizer to maintain a nice green color

 and healthy growth characteristics. During certain times of the year, it may require irrigation,

however, this may not be the case year round. Pesticides may be needed periodically, but their

 use can be minimized if other cultural practices (mowing, irrigation, fertilization) are done correctly.

Establishment

Although St. Augustine grass can be planted year-round in warmer sections of Florida,

the best time to plant is when environmental conditions allow for rapid establishment.

Allowing the grass to establish and develop a deep root system before it experiences

 temperature extremes will help it establish more quickly and with less water. In south

 Florida, the optimal time for establishment is during late fall, winter, or spring.

In central and north Florida, avoid establishment during cold winter or hot summer months.

It is important to provide frequent irrigation when grass is establishling. Multiple,

short irrigations throughout the course of the day for 7 to 10 days following planting

will help the grass establish. After the roots have pegged down, cut back frequency

 to once a day and increase the time to 1/4 to ½ inch for another 7 days. After this,

reduce frequency to 2 to 3 times weekly, again applying ¼ to ½ inch of water.

 Three to 4 weeks after sodding, the grass should be fully established and irrigation

 can begin on an “as-needed” basis. For more information on this,

see ENH 860 “Irrigation and Fertilization Requirements of Lawns and Landscapes.”

Do not mow the lawn until the roots have had a chance to peg down into the soil,

generally about 10 to 14 days after planting. Pegging means that the sod cannot

 be lifted without appreciable force. For more information on preparing the site and

establishment, refer to ENH03 “Establishing Your Florida Lawn.”

St. Augustine grass is established by vegetative propagation such as sod, plugs, or sprigs.

 Vegetative propagation means that instead of seeds, plant parts with growing points are

 used for planting. St. Augustinegrass has stolons (above-ground stems) that have

 areas of actively dividing cells at the nodes. These areas are capable of generating

new shoot growth and are responsible for lateral growth of St. Augustinegrass along the ground.

Sodding

Sodding is the instant method of establishment because it will produce an instant lawn.

 Although covered, the grass is still perishable at this stage. It is not yet safe for play or

 other activities and still needs to knit-in and root into the soil. Sodding reduces potential

weed competition that is observed when using other planting methods that leave bare ground.

 Sod should be laid over bare moist soil with pieces laid in a staggered bricklike pattern and

the edges fitted tightly together to avoid any open cracks. Rolling and watering thoroughly

 will ensure good contact with the soil for fast rooting.

 Figure 5. 

Sodding produces an instant lawn.

Sprigging

Sprigging is less expensive than sodding, but does not produce an instant lawn as does sodding.

 Sprigs contain nodes on stolons, which are planted end-to-end in furrows 6 to 12 inches apart.

Stolons should be covered with soil, but leaf blades should be left exposed. The soil should be

tamped and thoroughly saturated. Soil needs to be kept moist until growth of shoots and roots begins.

Plugging

A number of St. Augustinegrass cultivars are available commercially in garden centers 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 more quickly. 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.

Fertility

Proper fertilization of any lawngrass is an important component of the best management practices

 for your home lawn. Fertilization and other cultural practices influence the overall health of your

 lawn and can reduce or increase its vulnerability to numerous stresses, including weeds, insects,

and disease. If you apply your own fertilizer to your lawn, please note that any fertilizer that is

over-applied or does not get to the target has the potential to move as either leachate through

 the soil or as runoff on top of the soil. When this happens, nonpoint source pollution can result

and this can have a direct effect on surface and ground water quality. Refer to

Mowing

Proper mowing practices are necessary to keep any lawn healthy and attractive.

 Standard St. Augustine  ('BitterBlue', 'Classic', 'Floratam', 'Floratine',

'Palmetto', etc.) should be maintained at a height of 3.5 to 4 inches. Repetitively

mowing at lower heights reduces overall stress tolerance of the lawn, discourages

deep rooting, increases the chance for scalping if a mowing event is missed or

 postponed due to weather, and may increase susceptibility to pest problems.

 To obtain the correct height with most home rotary lawn mowers, use the

 highest wheel height setting. Maintaining the right height will help the grass

 develop a deep root system and give a better appearance to the turf.

 No more than a third of the leaf blades should be removed with any mowing.

 If possible, increase mowing height during periods of moisture stress or

 if the grass is growing in shade. Newer semidwarf varieties have a lower growth

habit, and should be mowed at 2 to 2.5 inches for optimum quality. Mowing too

infrequently and watering improperly can cause a thatch buildup.

 Figure 7. 

"Scalping" or mowing grass too short can injure your lawn. Always mow at the highest

 recommended height for your cultivar and species.

A rotary 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

monthly. St. Augustinegrass will require mowing weekly during the growing

season and less often during cooler months of the year. In north Florida,

 mowing may not be required during winter months.

Grass clippings should 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 put nutrients back into the soil system and may reduce turf

fertilization requirements by up to 25%. If clippings are excessive

 (e.g., clumping occurs), let them dry out and then disperse them over the lawn.

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 footprints) as the moisture begins to

 be depleted in the soil. If the lawn shows signs of slight wilting,

it is time to irrigate with ½ to ¾ inch of water. Do not water again

until the lawn shows signs of wilting. The amount of water applied

should not vary, but the frequency with which your lawn needs water

can vary due to season, soil type, grass species, temperature, etc.

For further information on recommended watering practices,

 refer to ENH9 “Watering Your Florida Lawn” and

 ENH63, “Let Your Lawn Tell You When to Water.”

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 make the lawn less

susceptible to damage by pests and environmental stresses.

If the diseases brown patch or gray leaf spot are a continuous

problem, excessive watering and nitrogen fertilization may be responsible.

Certain weeds, such as dollarweed and sedges, also thrive in soils that

are continuously wet.

 Figure 8. 

Let your lawn tell you when to water. Look for folded leaf blades as seen here.

Pest Problems

Other factors can also decrease the quality of a lawn. Excessive shade,

compacted soils, overwatering, improper mowing, traffic, and high or low pH

can all cause a lawn to perform poorly. It is important to recognize what the

 source of the problem is and to correct it if possible. For more information

on these types of stresses, refer to ENH153, “Environmental Stresses and Your Florida Lawn.”

Weeds

The best approach to weed control is a healthy, vigorous lawn. 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 labeled

specifically for St. Augustinegrass should be used. If an herbicide is needed,

 apply preemergence herbicides (i.e., pendimethalin, benefin, bensulide,

atrazine, or others) to control crabgrass if it was present in previous years.

Timing is critical for successful control. As a general rule, apply Feb. 1

in south Florida, Feb. 15 in central Florida, and March 1 in north Florida.

Note: Preemergence herbicides will not control weeds that are actively growing.

Apply postemergence herbicides (e.g., atrazine) as needed for control of

summer annual and perennial broadleaf or grassy weeds. Do not apply

 these materials if the turf is under moisture stress or if air temperatures exceed 85°F.

 Check with your local county cooperative extension office for positive weed identification

 and latest recommendations.

Many commercial “weed-n-feed” formulations will provide control, but they should be

used with caution because certain plant materials may not be tolerant.

These herbicides can damage landscape plants whose roots may extend

far under the lawn. Carefully read the label before use and follow all label

 directions. Refer to ENH884, “Weed Management in Home Lawns” for more information.

Insects

The major pest of St. Augustinegrass is the chinch bug. These are foliar-feeding

 insects that suck plant juices through a needlelike beak, causing yellowish to

 brownish patches in turf. Injured areas are usually first noticed as

 the weather begins to warm, in areas along sidewalks, adjacent to buildings,

 and in other water-stressed areas where the grass is in full sun.

 Figure 9. 

Chinch Bug Damage.

Check for chinch bugs by removing the ends of a coffee can, inserting one

end into the soil at the margin of suspected damaged areas, and filling with water.

 Chinch bugs will float to the water surface within five minutes. In areas where

 chinch bugs are a serious problem, a single, thorough insecticide treatment

may offer only temporary control. Therefore, repeat applications may be required.

 Some populations of this insect have become resistant to synthetic pyrethroid insecticides.

 Figure 10. 

Adult chinch bugs.

Other insect pests, including webworms, armyworms, grass loopers and mole

crickets can damage St. Augustinegrass. Mole crickets damage turfgrass areas

 primarily by creating tunnels or soft mounds while searching for food.

Additional damage may result from small animals digging through the soil profile

 in search of the mole crickets as food. Check for mole crickets by (1) examining

an area for the tunnels, or (2) applying 2 gallons of water mixed with 1½ ounces

 of detergent soap per 2 square feet in suspected damaged areas. Mole crickets

will surface in several minutes.

White grubs are another pest of St. Augustinegrass. These can be found by lifting

 the grass to a depth of about two inches. Grubs will be seen feeding on the roots

at this level. For more information on insect control, refer to

 ENY300, "Insect Pest Management on Turfgrass."

Diseases

Figure 11. 

Brown Patch symptoms on St. Augustinegrass.

Brown patch and gray leaf spot are 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.

Figure 12. 

Grey Leaf Spot symptoms on St. Augustinegrass.

Other St. Augustinegrass disease problems originate in the root system.

Take-all root rot (Gaeumannomyces graminis var. graminis) occurs under

high moisture or stress conditions. When symptoms are noticeable aboveground,

 the disease is usually in an advanced state. Following proper cultural

 practices is the best defense against this disease.

 Refer to SS-PLP-14, “Turfgrass Disease Management” for more information.

Nematodes

Several types of nematodes infest St. Augustinegrass lawns.

Population peaks of nematodes typically occur in late April to

early May and again in late August to early September.

 Damage symptoms include thin stand density, less vigorous growth,

 a weakened root system, slow recovery following rain or

 irrigation application, and certain weed invasions

 (e.g., prostrate spurge and Florida pusley).

Soil nematode levels can only be positively identified

through laboratory procedures. Your local county

 Extension service office can provide information

on submitting soil samples to the University of

 Florida Nematode Assay Laboratory.

 There are currently no effective nematode

controls for use in the home lawn.

Cultural controls include encouraging deep turfgrass rooting

 by raising the mowing height, irrigating less

frequently but more deeply, and providing ample soil potassium.

 For more information on nematodes,

refer to ENY006, “Nematode Management in Residential Lawns.”

Figure 13. 

Signs of nematode damage in St. Augustinegrass.

Other Problems

Many other factors can decrease the quality of a lawn.

To ensure 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.

Thatch Removal

Thatch is the layer of undecomposed leaf blades, stolons,

roots, and crowns intermingled with soil. Leaving mowing

 clippings on the lawn does not cause thatch because

 clippings are readily broken down by microbes in the soil.

 Thatch development is greatest in grass that is overfertilized,

overwatered, and improperly mowed. An excessive thatch layer

will reduce water penetration and can bind up fertilizer or pesticides.

In severe cases, you may see roots actually growing above ground

 and rooting into the thatch layer. This is a very unhealthy condition

and leaves a lawn vulnerable to many stresses.

 Figure 14. 

Thatch layers can develop in St. Augustinegrass, especially when

fertilization or irrigation rates are high.

Thank you for visiting http://www.SpringHillLawnAndLandscape.com

Joe,

352/  566- 8919   352/  263-1774

We take care of what you care about!

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Footnotes

1.

This document is Fact Sheet ENH5, a series of the Environmental Horticulture Department,

 Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences,

 University of Florida. First published: May, 1991. Revised: October, 2000; June, 2006

. Please visit the EDIS website at http://edis.ifas.ufl.edu.

2.

L.E. Trenholm, Associate Professor, Turfgrass Specialist, Department of Environmental

 Horticulture, Institute of Food and Agricultural Sciences, University of Florida, Gainesville,

FL 32611, J.B. Unruh, Associate Professor, Turfgrass Specialist, West Florida Research

and Education Center, Institute of Food and Agricultural Sciences, Jay, FL 32565,

 and J.L. Cisar, Professor, Turfgrass Specialist, Ft. Lauderdale Research and Education Center,

 Institute of Food and Agricultural Sciences, University of Florida, Ft. Lauderdale, FL 33314.

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