St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass, Coastal Erosion Control
Variety / Cultivar
Palmetto or Floratam (commonly cultivated turfgrass cultivars)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10, with high heat tolerance and sensitivity to hard freezes which cause winter dormancy and discoloration.
About This Grass
A coarse-textured, dense, sod-forming warm-season grass with a bright to dark green color. It has flat, blunt-tipped blades and forms a thick, spongy carpet. Unmowed, it can grow up to 6 to 12 inches high, but it is typically maintained much lower. Inflorescence is a flat, one-sided spike-like raceme.
Blade Characteristics
Coarse texture with wide blades (ranging from 4 to 10 mm wide), flat shape, blunt or rounded tips, bright green to blue-green color. Vernation is folded in the bud. The ligule is a fringe of hairs, auricles are absent, and the collar is continuous and broad.
Root System
Moderately deep fibrous root system originating from stolon nodes. Forms a thick thatch layer over time. Establishes rapidly from sod or plugs. Moderate drought tolerance, relies heavily on regular moisture for optimal appearance.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and tropical regions worldwide. Well-adapted to warm, humid tropical and subtropical climates.
Growth Habit
Stoloniferous, spreading aggressively via thick, above-ground runners (stolons) that form a dense, 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 sunlight). High water needs for best appearance; moderate drought tolerance by entering dormancy during severe dry spells. Prefers well-draining soils with a pH of 6.0 to 7.5.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches using a sharp rotary mower to avoid tearing the wide blades. High maintenance level due to regular watering, fertilization (2 to 4 lbs N per 1,000 sq ft annually), and periodic dethatching.
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance making it ideal for coastal areas, poor wear tolerance compared to Bermuda or Zoysia, moderate recovery from damage via stolons, and prone to chinch bugs and large patch disease.
Ecological Information
Introduced/cultivated widely in subtropical urban landscapes; provides moderate soil stabilization and erosion control in coastal sandy soils; generally not considered invasive in managed lawns, though stolons can invade adjacent flower beds.