St. Augustine Grass
Stenotaphrum secundatum · Warm-season (C4), Perennial
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on blade width and growth density
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy (turns brown) when temperatures drop below 55°F; susceptible to winter kill in northern regions.
About This Grass
A thick, coarse-textured grass that stays low to the ground. It features a deep blue-green to dark emerald color. The leaf blades are wide and have a slightly rounded appearance. When left unmowed, it produces spike-like seed heads.
Blade Characteristics
Coarse width (>4mm); folded vernation in the bud; leaf tips are distinctly rounded or blunt (boat-shaped); ligule is a fringe of short hairs; auricles are absent; blades are dark green and relatively stiff.
Root System
Shallow to moderate depth; fibrous root system that emerges from nodes along the stolons; high thatch-forming tendency; slows establishment if seeded, primarily established via sod or plugs.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; adapted to subtropical and tropical climates.
Growth Habit
Stoloniferous (spreads aggressively via thick above-ground runners); creates a dense, thick mat.
Sunlight & Water Needs
Prefers full sun but has excellent shade tolerance (for a warm-season grass); requires frequent watering (1 inch per week); moderate drought tolerance but wilts quickly without water.
Mowing & Maintenance
Ideal height: 2.5 to 4.0 inches; weekly mowing; requires 2-4 lbs of Nitrogen per 1000 sq ft annually; high maintenance due to water and pest needs.
Special Characteristics
Moderate traffic tolerance; high salt tolerance (excellent for coastal areas); prone to Large Patch (fungus) and Chinch Bug infestations; excellent at crowding out weeds when healthy.
Ecological Information
Native to coastal regions of the Americas and Africa; provides soil stabilization in sandy coastal soils; generally non-invasive in managed landscapes but can escape into wetlands in tropical zones; often used in monocultures.