St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine / Floratam (typical coarse-textured southern lawn variety)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Susceptible to freeze damage below 20°F and goes dormant or suffers winter kill in colder climates.
About This Grass
Forms a coarse-textured, dense, bright blue-green to apple-green turf. Typically maintained at a height of 2.5 to 4 inches, but can grow much taller if left unmowed. Produces a flattened, spike-like seed head at maturity.
Blade Characteristics
Blades are coarse (greater than 4mm wide), flat, with blunt, rounded tips. Vernation is folded in the bud. The ligule is a short fringe of hairs, and auricles are absent. The collar region is continuous and broad.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Prone to thatch accumulation under high fertilization and irrigation. Establishes rapidly from sod or plugs.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, the Caribbean, and the Mediterranean. Widely cultivated throughout the southern United States and tropical regions worldwide.
Growth Habit
Aggressively stoloniferous, spreading via thick above-ground runners (stolons) that form a coarse, dense turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). High water requirement to maintain green color and growth; moderate drought tolerance by entering dormancy during dry periods.
Mowing & Maintenance
Mow at 2.5 to 4 inches using a rotary mower. High maintenance level requiring regular fertilization (2 to 5 lbs N per 1000 sq ft per year), frequent watering, and periodic dethatching.
Special Characteristics
Moderate wear tolerance (lower than Bermuda or Zoysia), poor cold tolerance, excellent shade tolerance for a warm-season grass, highly susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/cultivated across the southern US coastal plains. Provides standard lawn ecosystem services, soil stabilization, and runoff reduction. Not typically invasive in natural settings outside cultivated zones.