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 similar common/dwarf cultivars like Floratam or Seville)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Susceptible to freeze damage below 20°F (-6°C); goes dormant and turns brown during cool winters.
About This Grass
A coarse-textured, dense, low-growing turfgrass with a bright blue-green to dark green color. It spreads rapidly via thick, flat stolons and forms a spongy, dense turf mat. Unmowed height can reach 6 to 12 inches, but it is typically maintained much lower. Produces flattened seed spikes at maturity.
Blade Characteristics
Blades are coarse (typically 4-10 mm wide), flat, with blunt, rounded tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar region is continuous and broad.
Root System
Moderately deep fibrous root system originating from stolon nodes. Tends to build up thatch quickly 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 called stolons) forming a thick, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses, needing at least 4 hours of direct sun). High watering needs for optimal appearance, moderate drought tolerance entering dormancy during severe dry spells. Prefers moist, fertile soils with a pH of 5.5 to 7.0.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches. Mowing frequency is weekly during the growing season. High maintenance level requiring regular fertilization, frequent watering, and periodic dethatching.
Special Characteristics
Moderate wear and traffic tolerance with slow recovery due to stolon-only spread. Excellent shade tolerance relative to other warm-season grasses. Good salt tolerance, making it popular in coastal regions. Vulnerable to chinch bugs, sod webworms, and large patch fungus.
Ecological Information
Introduced/cultivated across the American South. Provides ground cover and soil stabilization against erosion, particularly in sandy coastal soils. Serves as a habitat for urban wildlife and insects, though lower in native ecological diversity than native prairie grasses.