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' (most common wide-bladed cultivar with good drought and cold sensitivity)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10; excellent heat tolerance, poor cold tolerance with susceptibility to frost damage and winter dormancy discoloration; poorly suited for the transition zone except in mild coastal pockets.
About This Grass
Forms a dense, coarse-textured, blue-green to bright green turfgrass carpet with flat, wide blades and blunt tips. Unmowed height can reach 6 to 12 inches, but typically maintained lower. Produces flat seed spikes.
Blade Characteristics
Coarse texture with wide blades (4-10 mm), flat shape, blunt or rounded tips, folded vernation in the bud, light to dark green color, distinct parallel veins, continuous membranous ligule with a fringe of hairs, and absent or small auricles.
Root System
Moderately deep fibrous root system originating from nodes along the thick stolons; moderate to fast establishment from sod or plugs; forms a thick thatch layer requiring regular management; moderate drought tolerance with good recovery through stolons.
Growing Information
Origin Region
Native to tropical regions along the Gulf of Mexico, the Caribbean, and coastal areas worldwide; widely cultivated in the southern United States
Growth Habit
Stoloniferous, spreading aggressively via thick, above-ground stolons (runners) forming a coarse, dense turf mat
Sunlight & Water Needs
Prefers full sun but has the best shade tolerance among warm-season grasses (requires minimum 4 hours of direct sun); high water needs for optimal appearance, requiring about 1 inch of water per week; moderate drought tolerance by entering dormancy.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches using a sharp rotary mower; frequency is weekly during the growing season; fertilization requires 2 to 4 lbs N per 1000 sq ft annually; high thatch-forming tendency requiring periodic dethatching; medium-high maintenance level.
Special Characteristics
Good shade and salt tolerance, moderate wear tolerance but poor recovery compared to Bermuda grass, susceptible to chinch bugs, sod webworms, and take-all root rot; excellent erosion control in coastal sandy soils.
Ecological Information
Introduced and naturalized widely; provides good soil stabilization on coastal dunes and lawns; low wildlife food value compared to native prairie grasses; highly invasive in tropical island habitats; typically grown as a monoculture turf.