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 broad-bladed warm-season variety)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Good heat tolerance, poor cold tolerance (suffers freeze damage below 25°F).
About This Grass
St. Augustine grass is a coarse-textured, low-growing warm-season turfgrass known for its blue-green to dark green color and thick, flat stolons. It forms a dense, carpet-like turf that crowds out weeds effectively. Typical height ranges from 2 to 3 inches when maintained. At maturity, it produces flattened seed spikes.
Blade Characteristics
Blades are coarse, greater than 4mm wide (typically 6-10mm), flat, with rounded tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar is continuous and broad.
Root System
Moderate to deep fibrous root system originating from nodes on robust stolons. Moderate establishment speed from sod or plugs. Forms a thick layer of thatch if over-fertilized.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, the Caribbean, and coastal areas worldwide. Best adapted to warm, humid coastal climates.
Growth Habit
Stoloniferous (aggressive above-ground runners) forming a dense, coarse-textured sod and 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 water needs during active growth; moderate drought tolerance by entering dormancy during severe dry spells.
Mowing & Maintenance
Ideal mowing height is 2.5 to 3.5 inches using a sharp rotary mower. Medium to high maintenance level, requiring regular watering, moderate to high fertilization (2-4 lbs N per 1000 sq ft annually), and periodic dethatching.
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance (ideal for coastal properties), poor wear/traffic recovery compared to Bermuda or Zoysia, prone to chinch bugs and take-all root rot.
Ecological Information
Introduced/cultivated widely in southern regions. Provides good soil stabilization and erosion control on coastal sandy soils due to its dense stolon network. Used heavily in residential coastal lawns.