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
USDA Hardiness Zones 8 through 10, sensitive to severe cold (damage occurs below 20°F). Does not tolerate prolonged freezing temperatures well.
About This Grass
Coarse-textured, dense, low-growing warm-season turfgrass forming a thick carpet. Bright green to blue-green in summer, turning brown or going semi-dormant during cool winter months. Stems are flat and branching with distinctive flattened stolons.
Blade Characteristics
Coarse blades (greater than 4mm wide), flat with rounded or blunt tips, folded vernation in the bud, smooth texture, prominent midvein. Ligule is a fringe of hairs, auricles absent, collar is continuous and broad.
Root System
Moderate depth fibrous root system arising from stolon nodes. Forms a thick layer of thatch if not managed, establishes quickly from sod or plugs, moderate drought and wear tolerance compared to Bermuda.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, Caribbean, and Mediterranean; widely cultivated in the southern United States.
Growth Habit
Stoloniferous, spreading aggressively via thick above-ground runners (stolons) to form a dense, coarse-textured turf mat.
Sunlight & Water Needs
Full sun to moderate shade (more shade-tolerant than most warm-season grasses). High water requirement during active growth; moderate drought tolerance by entering dormancy. Prefers well-drained fertile soils with a pH of 6.0 to 7.5.
Mowing & Maintenance
Ideal mowing height 2.5 to 4 inches, mowed weekly during growing season. High fertilizer needs (4-6 lbs N per 1000 sq ft annually). Frequent dethatching needed due to aggressive stolon growth. High maintenance level.
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance (well-suited for coastal areas), poor wear tolerance compared to Bermuda or Zoysia, prone to chinch bugs and take-all root rot, excellent erosion control.
Ecological Information
Introduced/cultivated across the American Sunbelt. Provides standard urban wildlife cover, moderate soil stabilization in coastal zones, can become invasive in tropical wetland edges if unmanaged.