St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Coastal and Southern Residential Turf
Hardiness Zones
USDA Hardiness Zones 8 through 10. Susceptible to freeze damage below 25°F (-4°C), entering winter dormancy in the northern edges of its range where it turns brown until spring green-up.
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Variety / Cultivar
'Palmetto' or 'Floratam' St. Augustine (broad, coarse blades with high shade or heat adaptation depending on cultivar)
About This Grass
St. Augustine grass is a coarse-textured, low-growing warm-season turfgrass known for its blue-green to dark green color. Maintained lawns usually stand 2 to 3 inches tall, while unmowed turf can reach 6 to 12 inches. It forms a thick, carpet-like sod that crowds out many weeds when healthy.
Blade Characteristics
Blades are coarse, typically 4 to 10 mm 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, often whitish or pale green.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes rapidly from plugs or sod. Moderate to high thatch-forming tendency under high fertilization and watering.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and tropical regions worldwide. Well-adapted to the southern United States.
Growth Habit
Aggressively stoloniferous, spreading via thick above-ground runners (stolons) to form a dense, coarse-textured turf mat
Sunlight & Water Needs
Performs best in full sun, but is notably the most shade-tolerant warm-season turfgrass (tolerates partial shade, minimum 4 hours of direct sunlight). Requires regular watering, moderate drought tolerance with dormancy during extended dry spells, prefers well-drained soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower to prevent tearing the wide blades. Requires moderate to high maintenance, including 2 to 4 lbs of nitrogen per 1000 sq ft annually, periodic dethatching, and occasional aeration.
Special Characteristics
Excellent salt tolerance, making it popular for coastal properties. Moderate traffic and wear tolerance, but slower to recover from heavy damage compared to bermudagrass or zoysiagrass due to stolon-only spread. Good shade tolerance for a warm-season grass.
Ecological Information
Introduced and widely cultivated across southern coastal landscapes. Provides good soil stabilization and erosion control on sandy coastal soils. Serves as a habitat and forage resource for various urban wildlife and insects.