St Augustine Grass: Care, Cultivars, and Common Pests
St. Augustine grass (Stenotaphrum secundatum) is the broad-bladed, blue-green warm-season turf that dominates Gulf Coast and Florida lawns, prized for the most shade tolerance of any common warm-season grass and a thick carpet feel, but it is also the lawn most often killed by mowing too short, overwatering, or buying the wrong cultivar. This guide covers care, the right mowing height by cultivar, shade limits, the chinch bug and disease problems that actually matter, and how it stacks up against Bermuda and Zoysia, with numbers from university turf programs rather than sod-farm sales copy.
What is St. Augustine grass, and where does it grow?
St. Augustine grass is a warm-season turfgrass that spreads by above-ground runners called stolons, forming a dense, coarse-textured lawn. It grows across USDA hardiness zones 8 through 10, which covers Florida, the Gulf Coast, coastal Texas, the lower Southeast, and parts of coastal California. It is established from sod, plugs, or sprigs, not from seed in any reliable way, because viable seed has only recently and inconsistently come to market.
It earns its place for two reasons: it holds up to heat, humidity, and coastal salt better than most turf, and it tolerates filtered shade where Bermuda thins out. The trade-off is cold sensitivity. St. Augustine enters dormancy when temperatures stay below roughly 60 degrees Fahrenheit, light frost burns the leaf, and a hard freeze can kill stands at the northern edge of its range. That is why cultivar choice (covered below) matters as much as care.
What is the right mowing height for St. Augustine grass?
Mow St. Augustine grass at 2.5 to 4 inches, and match the height to your cultivar class: standard types like Floratam and Raleigh want 3.5 to 4 inches, semi-dwarfs like Palmetto sit at 2.5 to 3 inches, and true dwarfs like Seville, Delmar, and Captiva take 2 to 2.5 inches. Mowing too short is the single most common cause of St. Augustine decline, so when in doubt, mow high.
Never remove more than one-third of the blade in a single cut. Tall turf shades the soil, holds moisture, and crowds out weeds, which is why the 3.5 to 4 inch setting outperforms a close cut on most home lawns. Keep the mower blade sharp; St. Augustine’s wide blades shred and brown at the tips under a dull blade, which mimics disease.
| Cultivar class | Example cultivars | Mowing height | Best for |
|---|---|---|---|
| Standard | Floratam, Raleigh, Bitterblue | 3.5 to 4 in | Full sun, large open lawns |
| Semi-dwarf | Palmetto, CitraBlue | 2.5 to 3 in | Mixed sun and filtered shade |
| Dwarf | Seville, Delmar, Captiva | 2 to 2.5 in | Shade, finer texture, smaller yards |
How much sun and shade can it handle?
St. Augustine is the most shade-tolerant common warm-season grass, but it is not a shade grass. North Carolina State Extension and other turf programs put the floor at roughly 4 to 6 hours of direct or filtered light per day to survive. Standard cultivars like Floratam need 6 to 8 hours of direct sun to stay dense, while shade-selected types hold together on less.
If your problem area gets under 4 hours of light, no St. Augustine cultivar will thrive there long term. For those spots, thinning under tree canopy, or pet-worn ground, see our guide on getting grass to grow where it won’t before you re-sod and watch it fail again.
How do you water and fertilize St. Augustine grass?
Water deeply and infrequently: about 1 inch per week in spring and fall, up to 1 to 1.5 inches per week in peak summer, delivered in fewer, longer cycles rather than daily light sprinkles. In winter dormancy, 0.5 inch every 3 to 4 weeks is enough. Deep watering pushes roots down; daily shallow watering keeps them at the surface and invites chinch bugs and disease.
For fertility, apply 2 to 4 pounds of nitrogen per 1,000 square feet per year, split across 3 to 4 applications between roughly March and October. Keep any single application at or below 1 pound of nitrogen per 1,000 square feet, with at least half of it slow-release, to avoid burn and surge growth. Skip nitrogen during dormancy; feeding cold turf wastes product and feeds weeds.
- Late spring (after full green-up): first nitrogen application, around 1 lb per 1,000 sq ft.
- Early-to-mid summer: second application, slow-release favored to ride out heat.
- Late summer: third application as growth stays active.
- Early fall (about 6 weeks before first frost): final feed; stop nitrogen after this in cooler zones to harden the turf for winter.
If you are unsure how much product your lawn actually needs, measure first. Our walkthrough on measuring lawn square footage and calculating fertilizer keeps you from over-applying, which is the more expensive mistake.
What pests and diseases hit St. Augustine grass?
The southern chinch bug is the number one threat to St. Augustine grass, capable of building populations past 100 insects per square foot and killing turf in expanding yellow-to-brown patches, mostly in sunny, dry, stressed areas from roughly June through September. The major fungal problems are gray leaf spot, large patch (often called brown patch), and take-all root rot, each tied to specific weather and soil conditions.
One correction worth making, because most consumer pages get it wrong: Floratam was released by the Florida and Texas Agricultural Experiment Stations in 1973 as a chinch bug and SAD resistant selection, but it lost its chinch bug resistance decades ago and is now among the more susceptible cultivars. CitraBlue, Palmetto, and Captiva generally hold up better against chinch bugs over time. Chinch bug control usually means a labeled insecticide such as bifenthrin, paired with correcting the drought stress and short mowing that invited them.
| Problem | Signs | Favored by | First fix |
|---|---|---|---|
| Southern chinch bug | Expanding yellow-brown patches in sunny, dry spots | Heat, drought stress, June to September | Labeled insecticide; raise mowing height; water deeply |
| Gray leaf spot | Gray-to-brown oval leaf lesions | Days 77 to 86 F, nights above 65 F, humid and rainy | Cut nitrogen, improve airflow, fungicide if severe |
| Large patch (brown patch) | Circular yellow-brown rings | Cool, wet spring and fall | Reduce irrigation, fungicide on the ring edge |
| Take-all root rot (TARR) | Thinning that won’t green up; weak roots | Alkaline, poorly drained soil; stress | Lower soil pH toward 6.5 with sulfur, improve drainage, ease off water |
St. Augustine Decline (SAD), a virus disease, is the reason cultivars like Floratam and Raleigh exist at all. Raleigh was released by the North Carolina Experiment Station in 1980 as a cold-tolerant, SAD-resistant strain, which is why it remains the standard choice along the cooler northern edge of the grass’s range. If patches won’t green up in spring, work the soil and root issues (TARR, pH) before assuming insects. Our broader diagnosis guide for brown patches in a lawn walks the full decision tree.
St. Augustine vs Bermuda vs Zoysia: which should you pick?
Pick St. Augustine for shade tolerance and a thick, coarse coastal lawn; pick Bermuda for full sun, heavy traffic, and drought; pick Zoysia for a dense, slower-growing, lower-input lawn that splits the difference. The right answer comes down to sunlight, foot traffic, and how much mowing and water you will accept.
| Factor | St. Augustine | Bermuda | Zoysia |
|---|---|---|---|
| Shade tolerance | Best of the three (4 to 6 hrs min) | Poor (needs 6 to 8 hrs sun) | Moderate |
| Drought tolerance | Moderate, needs steady water | High | High, goes dormant and recovers |
| Traffic tolerance | Lower, normal foot traffic only | High, fast recovery | High but slow to repair |
| Mowing height | 2.5 to 4 in | 0.5 to 2.5 in | 1 to 2.5 in |
| Spreads by | Stolons only, no seed | Stolons and rhizomes, seed available | Stolons and rhizomes |
| Main pest issue | Chinch bugs | Mites, armyworms | Thatch buildup, billbugs |
| Cold tolerance | Poor (Raleigh is best) | Better | Best of the three |
In short: a shaded coastal yard with normal use leans St. Augustine; a sunny, kid-and-dog-trafficked lawn leans Bermuda; a homeowner who wants the lowest mowing frequency and a soft, dense surface leans Zoysia. For the seasonal feeding and mowing calendar that applies once you have picked, our year-round grass maintenance schedule by grass type lays out the warm-season cadence.
How much does St. Augustine sod cost, and how do you establish it?
St. Augustine sod runs roughly $0.45 to $0.90 per square foot for material, or about $200 to $405 per pallet, with a pallet covering 400 to 500 square feet. Installed, expect $0.95 to $2.40 per square foot depending on site prep and labor. A pallet weighs 2,000 to 2,500 pounds, and more when wet, so delivery and handling matter on the quote.
Because St. Augustine does not establish from seed reliably, you install it as sod for instant cover or as plugs spaced on a grid that fill in over a season by stolon spread. Lay sod on bare, raked, lightly moist soil with tight seams, then keep it damp (not soaked) for the first two to three weeks while roots knit. For regional pricing on installation and full lawn projects, see our 2026 lawn care cost benchmarks.
- Test and, if needed, correct soil pH toward 6.0 to 6.5 before laying.
- Remove old turf and weeds, then grade and rake to a smooth, slightly moist bed.
- Lay sod in a staggered brick pattern with tight seams, or set plugs on a 12 to 18 inch grid.
- Roll lightly for soil contact, then water daily in short cycles for 2 to 3 weeks.
- Taper to deep, infrequent watering and hold off on nitrogen until the turf is rooted and growing.
Last reviewed: June 2026
HMNDP Editorial Team, reviewed by HMNDP turf and horticulture editors.
Frequently asked questions
How often should you water St. Augustine grass?
Water deeply and infrequently: about 1 inch per week in spring and fall and up to 1 to 1.5 inches per week in peak summer, delivered in fewer, longer cycles rather than daily light sprinkles. In winter dormancy, 0.5 inch every 3 to 4 weeks is plenty. Daily shallow watering keeps roots at the surface and invites chinch bugs and disease.
What is the best mowing height for St. Augustine grass?
Mow at 2.5 to 4 inches and match the height to your cultivar. Standard types like Floratam and Raleigh want 3.5 to 4 inches, semi-dwarfs like Palmetto sit at 2.5 to 3 inches, and dwarfs like Seville and Captiva take 2 to 2.5 inches. Mowing too short is the most common cause of St. Augustine decline, so mow high when unsure.
How do you make St. Augustine grass spread and thicken?
Mow high at 3.5 to 4 inches, water deeply once or twice a week totaling 1 to 1.5 inches, and feed 2 to 4 pounds of nitrogen per 1,000 square feet across 3 to 4 applications from spring through early fall. St. Augustine spreads by above-ground stolons, so healthy, unstressed turf fills bare spots on its own over a season.
Is St. Augustine grass good for shade?
It is the most shade-tolerant common warm-season grass, but it still needs roughly 4 to 6 hours of direct or filtered light per day to survive. Shade-selected cultivars like Palmetto, Seville, and Bitterblue hold up best. Below 4 hours of light, no St. Augustine cultivar will thrive long term, so address the canopy or choose another ground cover.
Can you grow St. Augustine grass from seed?
Not reliably. St. Augustine is established from sod, plugs, or sprigs because viable seed has only recently and inconsistently reached the market. Sod gives instant cover; plugs set on a 12 to 18 inch grid fill in over a season as the stolons spread. Plan on sod or plugs rather than a seed bag for a dependable lawn.
What is killing my St. Augustine grass?
The most common cause is the southern chinch bug, which kills turf in expanding yellow-brown patches in sunny, dry spots from June to September. Mowing too short and overwatering rank close behind. Fungal issues like gray leaf spot, large patch, and take-all root rot account for most of the rest. Diagnose the pattern and conditions before treating.
Is Floratam still chinch bug resistant?
No. Floratam was released in 1973 as a chinch bug and SAD resistant selection, but it lost its chinch bug resistance decades ago and is now among the more susceptible cultivars. CitraBlue, Palmetto, and Captiva generally hold up better against chinch bugs over time, so resistance should drive cultivar choice in chinch bug country.
St. Augustine vs Bermuda vs Zoysia: which is best?
Pick St. Augustine for shade tolerance and a thick coastal lawn, Bermuda for full sun, heavy traffic, and drought, and Zoysia for a dense, slower-growing, lower-input lawn. St. Augustine needs steady water and only normal foot traffic, while Bermuda recovers fastest and Zoysia mows least often. Sunlight and traffic decide the winner.