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 coarse variety)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F; very high heat tolerance.
About This Grass
A coarse-textured, low-growing turfgrass with a vibrant medium-to-dark green color. It forms a thick, spongy sod and features blunt, rounded leaf tips and thick stems. When unmowed, it produces short, spike-like seed heads (racemes) that are relatively inconspicuous.
Blade Characteristics
Coarse width (>4mm), flat shape with a distinct boat-shaped or rounded tip. Leaf color is medium green. Vernation is folded in the bud; ligule is a short fringe of hairs; auricles are absent; the collar is constricted and often light green/white.
Root System
Fibrous and moderately deep, primarily arising from the nodes of stolons. High thatch-forming tendency; moderate establishment speed; excellent wear recovery due to aggressive stolon growth.
Growing Information
Origin Region
Native to the Gulf of Mexico region, West Indies, and Western Africa; best in tropical and subtropical coastal climates.
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners/stolons); rapidly forms a dense, carpet-like mat.
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses); needs 4-6 hours of sun; high water requirement; moderate drought tolerance but wilts quickly without moisture; prefers slightly acidic to neutral soil (pH 6.0-7.5).
Mowing & Maintenance
Ideal height 2.5-4.0 inches; weekly mowing frequency; 2-4 lbs Nitrogen per 1000 sq ft per year; high maintenance level due to water and pest needs; periodic vertical mowing to manage thatch.
Special Characteristics
Excellent shade tolerance compared to other warm-season grasses; high salt tolerance (ideal for coastal areas); susceptible to Large Patch (fungus) and Chinch Bugs; poor traffic tolerance compared to Bermuda grass.
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in sandy coastal areas; low wildlife value; generally non-invasive in non-tropical climates; often grown as a monoculture rather than in blends.