St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Floratam' (a popular coarse-textured cultivar known for its bright green color and resistance to St. Augustine decline virus)
Hardiness Zones
USDA Hardiness Zones 8 through 10 (and warm parts of Zone 7). Low cold tolerance compared to cool-season grasses; goes dormant and can suffer freeze damage below 25°F (-4°C). Highly suited for coastal, humid regions.
About This Grass
A coarse-textured, low-growing turfgrass that forms a dense, carpet-like lawn. It features broad, flat leaf blades with blunt tips and a vibrant blue-green to dark green color in summer, turning brown and going dormant under frost or prolonged drought. Unmowed, it can grow up to 6-12 inches tall, but it is typically maintained much lower. Seed heads are formed on flat, spike-like racemes.
Blade Characteristics
Blades are wide (coarse, >4mm), flat, with rounded or blunt tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar region is continuous, narrow, and often yellowish-green.
Root System
Moderately deep fibrous root system originating from stolon nodes. Tends to build up thatch quickly if over-fertilized. Establishes rapidly from sod or plugs. Forms a tough, spongy sod that provides decent wear tolerance though slower recovery than Bermuda grass.
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 (spreads aggressively via thick above-ground runners called stolons) forming a dense, coarse turf mat
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most other warm-season grasses, needing at least 4 hours of direct sun). High water requirement; susceptible to drought and will go dormant or wilt quickly without adequate irrigation. Thrives in moist, well-draining soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches, mowed weekly during the growing season. Fertilization requires 2 to 4 lbs N per 1000 sq ft annually. Regular dethatching and core aeration are recommended due to heavy thatch accumulation. Maintenance level is medium-high.
Special Characteristics
Good shade and salt tolerance compared to other warm-season lawns. Moderate wear tolerance, but slow recovery from heavy damage. Susceptible to chinch bugs, sod webworms, take-all root rot, and brown patch. Excellent for home lawns, coastal properties, and southern landscapes.
Ecological Information
Introduced species in many non-native regions. Provides ground cover and soil stabilization against wind and water erosion, especially in coastal environments. Offers limited wildlife food value compared to native prairie grasses, but forms protective cover for small insects and ground-dwelling fauna.