St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Palmetto' or 'Floratam' St. Augustine (common coarse-textured turf cultivars)
Hardiness Zones
USDA Hardiness Zones 8 through 10. Highly sensitive to freezing temperatures, entering winter dormancy or suffering winter kill in colder zones. Does not tolerate heavy frost well.
About This Grass
Forms a dense, coarse-textured, blue-green to bright green turf carpet. Unmowed height can reach 6-12 inches, but when maintained it is kept much lower. Has flat blades and forms a thick, spongy lawn over time.
Blade Characteristics
Coarse texture with wide blades (often 4-10 mm wide), flat shape, blunt or rounded tips, folded vernation in the bud, light to dark blue-green color, with a prominent midrib. Ligule is a fringe of hairs, and auricles are absent.
Root System
Moderately deep fibrous root system originating from stolon nodes. Prone to thatch accumulation if over-fertilized. Establishes rapidly from sod or plugs.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, Caribbean, and Mediterranean; widely cultivated in the southern United States.
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a thick, coarse, dense turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). High water needs during active growth, with moderate drought tolerance by entering dormancy during dry spells. Prefers well-drained soils with a pH of 5.5 to 7.5.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches. Requires regular mowing during the growing season, moderate to high fertilization (2-5 lbs N per 1000 sq ft annually), frequent dethatching due to rapid stolon growth, and medium-high overall maintenance.
Special Characteristics
Excellent shade tolerance compared to other warm-season grasses and good salt tolerance for coastal areas. Moderate wear tolerance, but slower recovery from heavy damage than Bermuda grass due to stolon-only spread.
Ecological Information
Introduced and naturalized in warm coastal areas. Provides good soil stabilization and erosion control on coastal sandy soils. Can become invasive in natural tropical wetlands if allowed to escape cultivation.