St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Floratam (most common coarse-textured cultivar)
Hardiness Zones
USDA Hardiness Zones 8-10, sensitive to hard frosts and extreme cold (suffers freeze damage below 25F). Not suitable for the transition zone.
About This Grass
Forms a lush, dense carpet of coarse-textured turf with a bright to dark green color. Height ranges from 2 to 3 inches when maintained. Produces flat, thick stems and terminal spike-like seed heads at maturity.
Blade Characteristics
Coarse blades greater than 4mm wide, flat shape, blunt or rounded tips, bright green to blue-green color, folded vernation in the bud, short membranous ligule with a fringe of hairs, and absent auricles.
Root System
Moderately deep fibrous root system originating from stolon nodes. Prone to thatch accumulation if over-fertilized. Moderate establishment speed, forms a thick sod that handles moderate wear.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, Caribbean, and Mediterranean. Performs best in coastal and warm humid climates.
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a dense, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than Bermuda or Zoysia). High water needs during active growth, moderate drought tolerance with dormancy in severe dry spells. Prefers well-drained soils with pH 6.0-7.5.
Mowing & Maintenance
Ideal mowing height between 2.5 and 4 inches using a sharp rotary mower. Medium to high maintenance level, requiring 2-5 lbs N per 1000 sq ft annually, regular irrigation, and occasional dethatching.
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance (ideal for coastal regions), poor wear tolerance compared to Bermuda, susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/naturalized in many subtropical areas. Provides good soil stabilization and erosion control on coastal sites. Forms a monolithic lawn cover with limited native wildlife value compared to native prairies.