St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass, Erosion Control
Variety / Cultivar
Floratam (widely used cultivar known for its coarse texture and purple stolons)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Exhibits low cold tolerance and goes dormant (turns brown) with frost.
About This Grass
St. Augustine grass features a coarse texture, broad flat blades, and a vibrant blue-green to dark green color. It forms a dense, spongy turf canopy when properly maintained. Unmowed, it can grow up to 6 to 12 inches tall with upright seed stalks bearing flat spike-like racemes.
Blade Characteristics
Blades are broad (typically 4-10 mm wide), flat with blunt or rounded tips, and folded in the bud (vernation). The collar region is continuous with a very short, membranous ligule fringed with hairs, and auricles are absent.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes relatively quickly from sod or plugs, forms a moderate thatch layer, and provides good soil stabilization.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of the southeastern United States, the Caribbean, and tropical regions worldwide. Best adapted to warm, humid coastal climates.
Growth Habit
Stoloniferous, spreading aggressively by above-ground runners (stolons) to form a thick, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). High water needs for optimal appearance, with moderate drought tolerance by entering dormancy during severe dry spells.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower. High maintenance level requiring regular irrigation, moderate to high fertilization (2-5 lbs N per 1000 sq ft per year), and periodic dethatching.
Special Characteristics
Fair traffic and wear tolerance (recovers via stolons but slower than Bermuda), poor cold tolerance, moderate salt spray tolerance, excellent shade tolerance for a warm-season grass, susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced and widely cultivated in tropical and subtropical regions. Provides good erosion control on sandy coastal soils, moderate wildlife cover, and forms dense monocultures that naturally crowd out many weeds.