St. Augustine Grass Lawn Care Guide
Published: June 6, 2026
The dominant lawn grass along the Gulf Coast and Florida. Coarse-bladed, shade-tolerant, and thrives in humid subtropical climates.
About St. Augustine Grass
Scientific name: Stenotaphrum secundatum
Origin: Native to coastal regions of the Gulf of Mexico and the Mediterranean
St. Augustine grass is the dominant lawn species along the Gulf Coast and throughout Florida. Its broad, coarse blades give it a distinctive tropical look, and it is one of the few warm-season grasses that performs well in partial shade. St. Augustine spreads aggressively through above-ground stolons and establishes quickly from sod, though it is not available as seed. It thrives in humid, subtropical climates and is moderately drought-tolerant once established. Homeowners love it for its rapid fill-in and lush green colour, but it does require regular watering and is susceptible to chinch bugs and brown patch fungus. Cultivar choice matters more for St. Augustine than for any other warm-season grass: Floratam (the long-time Florida standard) tolerates full sun and chinch bugs well but has poor shade tolerance and is susceptible to gray leaf spot; Palmetto offers better shade tolerance and finer texture; Raleigh is the most cold-tolerant cultivar, extending the species' usable range to upper zone 8a; Bitter Blue and Seville are dwarf cultivars producing finer-textured lawns suited to manicured residential settings. Salt tolerance is a significant strength, St. Augustine is the default lawn grass for oceanfront and intracoastal properties from Texas through Florida and along the Carolina coast.
St. Augustine Grass Growing Zones
St. Augustine Grass performs best in USDA hardiness zones 8b, 9a, 9b, 10b. These zones provide the right combination of temperature range, growing season length, and winter conditions for St. Augustine Grass to thrive.
As a warm-season grass, St. Augustine Grass enters dormancy when soil temperatures drop below 55°F and actively grows when temperatures are between 80°F and 95°F. Planting outside its recommended zones may result in winter kill or poor summer performance.
Select your city below to see a care guide tailored to your local climate, soil conditions, and growing season.
Monthly Mowing Guide for St. Augustine Grass
The recommended mowing height for St. Augustine Grass is 3–4 in. Below is a month-by-month mowing schedule based on typical warm-season growth patterns. The current month is highlighted in green.
| Month | Mow? | Height | Notes |
|---|---|---|---|
| January | No | - | Dormant, do not mow |
| February | No | - | Dormant, do not mow |
| March | Start | Low (scalp) | Scalp lawn to remove dead material as green-up begins |
| April | Yes | 3–4 in | Resume regular mowing as growth increases |
| May | Yes | 3–4 in | Peak growth begins, mow every 5–7 days |
| ▶ June | Yes | 3–4 in | Peak season, maintain consistent schedule |
| July | Yes | 3–4 in | Peak season, mow frequently |
| August | Yes | 3–4 in | Peak season continues through late summer |
| September | Yes | 3–4 in | Growth begins to slow as days shorten |
| October | Reduce | 3–4 in | Slow growth, mow as needed |
| November | Reduce | 3–4 in | Final mow before dormancy in most areas |
| December | No | - | Dormant, do not mow |
Watering St. Augustine Grass
St. Augustine grass needs 1 to 1.5 inches of water per week, making it one of the thirstier warm-season options. Water deeply two to three times per week, ideally in the early morning to reduce fungal risk. Wilting blade tips and a blue-grey colour indicate drought stress. In sandy soils you may need to water more frequently because moisture drains quickly through the root zone. The 1.5-inch weekly target is the single biggest practical limitation of St. Augustine in 2026: under SWFWMD Phase III restrictions in Florida (one watering day per week) and Stage 2 to 3 restrictions across Texas, hitting that target legally is difficult. Cycle-and-soak irrigation (3 short cycles of 10 to 15 minutes with 30 minute pauses between) helps water penetrate deeply on heavy clay or compacted soils without runoff. Smart controllers with rain sensors and ET-based scheduling can cut irrigation by 20 to 30 percent without reducing turf quality and are increasingly required by municipal codes in Florida and coastal Texas.
Fertilizing St. Augustine Grass
Apply 2 to 4 pounds of nitrogen per 1,000 square feet per year to St. Augustine, split into three to four applications from spring through early fall. Use a fertiliser containing iron for enhanced green colour without excessive growth. St. Augustine is susceptible to iron chlorosis in alkaline soils, so a fertiliser with chelated iron can help. Stop fertilising at least six weeks before the first expected frost. In Florida, follow the regional fertilizer ordinances that restrict phosphorus and limit summer nitrogen applications to slow-release sources (typically a 50% slow-release minimum from June through September). The Florida-Friendly Landscaping Program guidelines call for 2 to 4 pounds of N annually depending on cultivar and soil, Floratam tolerates the upper end while Palmetto and Seville prefer the lower end. Avoid weed-and-feed products containing atrazine after May 1 in coastal Florida, as the herbicide leaches into groundwater under summer rainfall conditions and is restricted by many municipal codes.
Soil Preparation and Site Selection for St. Augustine Grass
St. Augustine prefers slightly acidic to neutral soils with a pH between 6.0 and 7.0, and tolerates the alkaline soils common in central Florida and South Texas. The species thrives in sandy, well-drained soils that are typical of its native Gulf Coast range. Heavy clay soils need significant amendment (3 to 4 inches of compost worked into the top 8 inches) plus core aeration after establishment to prevent waterlogging. Site selection is critical: St. Augustine handles 4 to 6 hours of dappled sunlight depending on cultivar, but full deep shade kills it. Salt tolerance is exceptional, making it the default choice for oceanfront lawns.
How to Establish a St. Augustine Grass Lawn
St. Augustine is not commercially available as seed and must be installed as sod or plugs. Sod provides immediate coverage at $0.50 to $1.00 per square foot installed and is the dominant choice for whole-lawn renovations. Plugs (3-inch sod squares) cost $0.30 to $0.60 each and are planted on 12-inch centers, with full coverage requiring 4 to 6 months of careful management. Both methods should be installed in late spring (April to June in Florida, May to June in Texas and Carolina) when soil temperatures are consistently above 65°F. Water sod lightly twice daily for the first 2 weeks, then transition to deep weekly watering. Avoid heavy foot traffic for the first 30 days.
Seasonal Care Calendar for St. Augustine Grass
Spring
March-May. Apply pre-emergent in late February in Florida or mid-March in coastal Texas and Carolina. Begin regular mowing at 3 to 4 inches as growth resumes. First nitrogen application (1 pound of N per 1,000 sq ft) in mid-April after full green-up. Inspect for chinch bug damage as temperatures warm, treat with bifenthrin if damage is detected.
Summer
June-August. Peak growing season. Mow every 5 to 7 days at 3 to 4 inches. Apply 1 pound of N per 1,000 sq ft in mid-June (use slow-release sources to comply with Florida summer fertilizer ordinances). Irrigate 1.5 inches per week. Inspect monthly for chinch bugs (most damaging June through August) and brown patch fungus. Apply azoxystrobin if circular patches develop.
Fall
September-November. Final nitrogen application in early September (1 pound of N). Reduce mowing to every 7 to 10 days as growth slows. Apply potassium fertilizer in October to build winter hardiness. Stop fertilizing 6 weeks before first expected frost. Final mow at 3 to 3.5 inches before dormancy.
Winter
December-February. St. Augustine slows dramatically or goes dormant depending on zone. In Zone 9b to 10b, may continue light growth requiring occasional mowing. In Zone 8b to 9a, full dormancy with brown color. Avoid foot traffic on dormant turf. Apply pre-emergent in late February before spring weed germination.
Common Problems with St. Augustine Grass
Chinch Bug Damage
Irregular brown patches that spread outward, caused by southern chinch bugs feeding on grass blades.
Solution: Apply bifenthrin or imidacloprid when damage is first noticed. Water before treatment to bring bugs to the surface. Maintain a healthy lawn to resist infestations.
Brown Patch Fungus
Circular brown patches 1 to 3 feet in diameter that appear during warm, humid weather.
Solution: Reduce watering frequency, avoid evening irrigation, improve air circulation, and apply a fungicide labelled for Rhizoctonia if symptoms persist.
SAD Virus (St. Augustine Decline)
Mottled yellow and green patterns on blades, stunted growth, and thinning turf caused by Panicum Mosaic Virus.
Solution: There is no cure for SAD virus. Replace affected areas with a resistant cultivar such as Floratam, Palmetto, or Raleigh.
Common pests: Learn how to get rid of chinch bugs in St. Augustine, or browse all lawn pest guides.
Is St. Augustine Grass Right for Your Lawn?
Pros
- +Best shade tolerance of warm-season grasses
- +Fast establishment from sod
- +Lush, tropical appearance
- +Thrives in humid subtropical climates
Cons
- –Not available from seed
- –Susceptible to chinch bugs and brown patch
- –Moderate drought tolerance requires regular watering
- –Coarse texture is not to everyone’s taste
Maintenance level: medium | Growth rate: fast | Texture: Coarse | Drought tolerance: medium | Shade tolerance: high
FAQ, St. Augustine Grass Common Questions
What zones does St. Augustine grass grow in?
St. Augustine thrives in USDA zones 8b through 10b, performing best in humid subtropical and tropical climates. It is the dominant lawn grass in Florida, along the Gulf Coast, and in parts of Southern California.
Can St. Augustine grass grow from seed?
St. Augustine is not commercially available as seed and must be established from sod or plugs. Sod provides instant coverage and is the most common installation method. Plugs are cheaper but take several months to fill in completely.
How do I fix brown patch in St. Augustine?
Brown patch is a fungal disease caused by Rhizoctonia solani that thrives in humid conditions. Reduce watering frequency, improve air circulation by pruning nearby shrubs, avoid late-evening irrigation, and apply a fungicide labelled for brown patch if the problem persists.
How tall should I mow St. Augustine grass?
Mow St. Augustine at 3 to 4 inches for standard cultivars or 2 to 3 inches for dwarf varieties like Seville. Taller mowing heights promote deeper roots and better shade tolerance. Never remove more than one-third of the blade length in a single mowing.
What kills chinch bugs in St. Augustine?
Chinch bugs are the most damaging pest of St. Augustine grass, causing large irregular brown patches. Apply a granular or liquid insecticide containing bifenthrin or imidacloprid when damage is first noticed. Water the lawn before treatment to bring chinch bugs to the surface.
Which St. Augustine cultivar handles shade best?
Palmetto and Sapphire are the leading shade-tolerant St. Augustine cultivars, performing well in 4 hours of dappled sunlight. Floratam, the long-time Florida standard, requires 6 or more hours of direct sun and thins quickly in shade. For the deepest shade conditions, Bitter Blue is the most shade-tolerant cultivar but is harder to source. Match the cultivar to the sun exposure of your yard, putting Floratam in shade or Palmetto in full sun produces predictably disappointing results.
How do I water St. Augustine to prevent brown patch?
Brown patch fungus thrives on wet leaf blades during humid evenings. Water only in early morning (before 10 AM), apply 1.5 inches per week in 2 deep sessions rather than daily light irrigation, and avoid running sprinklers in late afternoon or evening. Improve air circulation by pruning overhanging branches and shrubs. If brown patch appears (circular brown patches 1 to 3 feet across), apply azoxystrobin or propiconazole fungicide and reduce nitrogen fertilization until the disease subsides.
Drought Survival
Drought tolerance rating: 5/10
St. Augustine has shallow roots (8-12 inches) and is less drought-tolerant than Bermuda or zoysia. Survives 14-21 days without water before showing severe stress; rarely tolerates more than 30 days dormancy. Better suited to Gulf Coast humidity than dry-heat regions.
Under Stage 2 restrictions, requires more careful management than other warm-season grasses. Cycle-and-soak watering described in our water restrictions guide is essential to push limited water to the shallow root zone. Confirm dormancy via the tug test in our dead-or-dormant guide before assuming death.