St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' (Standard broad-leaf cultivar)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; will go dormant and turn brown when temperatures drop below 55°F; enters true dormancy after frost.
About This Grass
A coarse-textured, low-growing grass with a dense, carpet-like appearance. It remains bright green during the growing season and turns brown/dormant in frost. Seed heads are inconspicuous spikes with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse width (8-10mm); flat shape with a distinct rounded or blunt tip; medium to dark green color; folded vernation; fringe of hairs for a ligule; auricles absent; constricted collar.
Root System
Moderately deep fibrous roots originating from stolon nodes; high thatch-forming tendency; slow to moderate establishment speed; fair wear recovery via stolon creeping.
Growing Information
Origin Region
Coastal regions of Africa, the Americas, and the Caribbean; common in US Gulf Coast and California.
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners); heavy mat-forming habit.
Sunlight & Water Needs
Full sun to partial shade (one of the most shade-tolerant warm-season grasses); high water needs; moderate drought tolerance; prefers acidic to neutral pH (5.0-8.5).
Mowing & Maintenance
Mowing height 2.5–4.0 inches; weekly frequency; medium maintenance; requires 2-4 lbs N/1000 sq ft annually; needs periodic dethatching.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (excellent for coastal areas); poor traffic tolerance; prone to Chinch bugs and Large Patch disease.
Ecological Information
Native to tropical coastal regions; provides excellent soil stabilization; can be invasive in non-native wetland margins; often grown as a mono-stand rather than a blend.