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' (coarse-textured, deep green, very popular in Florida and southern regions)
Hardiness Zones
USDA Hardiness Zones 8 through 10. Excellent heat tolerance, but poor cold tolerance, suffering winter dormancy and potential freeze damage below freezing temperatures. Not suitable for the transition zone.
About This Grass
St. Augustine grass is a coarse-textured, low-growing, aggressive turfgrass that forms a dense, carpet-like lawn. It features broad blades with blunt tips and a vibrant blue-green to dark green color. Unmowed, it can reach heights of 6 to 12 inches, but when maintained it is typically kept between 2.5 to 4 inches. Seed heads appear as flat, spiked racemes on slender stalks.
Blade Characteristics
Blades are broad (coarse, generally >5mm wide), flat, with rounded or blunt boat-shaped tips. Color ranges from bright blue-green to dark green. Vernation is folded in the bud. The ligule is a fringe of hairs, auricles are absent, and the collar is continuous and broad.
Root System
Moderately deep fibrous root system originating from thick surface stolons. Moderate establishment speed from sod or plugs. Forms a thick, spongy thatch layer over time if not managed properly. Good sod-forming capability.
Growing Information
Origin Region
Native to tropical and subtropical coastal regions of the Americas and West Africa; widely cultivated throughout the southern United States and the Gulf Coast.
Growth Habit
Stoloniferous, spreading rapidly via thick surface runners (stolons) to form a coarse, dense turf mat.
Sunlight & Water Needs
Performs best in full sun, but has the highest shade tolerance among warm-season grasses (requires a minimum of 4 hours of direct sunlight). Requires regular, moderate to high watering (about 1 inch per week) and has moderate drought tolerance, entering dormancy during extended dry periods. Prefers well-draining soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower with sharp blades. Mowing frequency is every 5 to 7 days during peak growing season. Requires 2 to 4 lbs of nitrogen per 1000 sq ft annually. Medium-high maintenance level due to susceptibility to thatch buildup, pests (like chinch bugs), and fungal diseases.
Special Characteristics
Moderate to low traffic/wear tolerance (stolons easily damaged by heavy foot traffic). Good salt tolerance, making it popular for coastal areas. Exceptional shade tolerance relative to other warm-season grasses. Susceptible to chinch bugs, take-all root rot, and brown patch.
Ecological Information
Introduced and naturalized in many tropical and subtropical regions. Provides moderate wildlife cover in residential landscapes, excellent soil stabilization on coastal sandy soils, and serves as a dependable erosion control groundcover in warm coastal environments.