St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Floratam (coarse, bright green, highly popular cultivar with purple-tinted stolons)
Hardiness Zones
USDA Hardiness Zones 8 through 10. Excellent heat tolerance, poor cold tolerance, goes dormant and discolors with frost, susceptible to freeze damage below 20F.
About This Grass
Forms a thick, lush, carpet-like turf with coarse texture and bright to blue-green color. Leaf blades are flat, wide, and blunt-tipped. Unmowed height reaches 6 to 12 inches. Produces a flattened spike seed head.
Blade Characteristics
Blades are coarse (>5mm wide), flat, with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs. Auricles are absent. The collar region is continuous and broad.
Root System
Moderately deep fibrous root system originating from stolon nodes. Prone to thatch accumulation if over-fertilized. Moderate establishment speed from sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of the southeastern United States, and the Caribbean. Cultivated globally in tropical and subtropical regions.
Growth Habit
Stoloniferous, spreading rapidly via aggressive, thick surface stolons to form a dense, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). High water needs during establishment and dry periods; moderate drought tolerance with some dormancy under severe stress. Prefers moist, well-draining soils with a pH of 6.0 to 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower to prevent tearing the wide blades. High maintenance level requiring regular fertilization (3 to 5 lbs N per 1000 sq ft per year), frequent watering, and periodic dethatching.
Special Characteristics
Low to moderate wear tolerance compared to Bermuda or Zoysia. Good shade tolerance for a warm-season grass. Susceptible to chinch bugs, sod webworms, and Take-All Root Rot. Forms a dense turf that effectively crowds out weeds when healthy.
Ecological Information
Introduced and naturalized in many tropical regions worldwide. Provides good soil stabilization and erosion control in coastal sandy soils. Low wildlife food value compared to native grasses, primarily functions as ornamental and utility lawn turf.