St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common Floratam type (likely high-UV tolerant naturalized variety)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass that forms a dense, thick sod. It has a vibrant medium to dark green color and remains green longer into the fall than other warm-season grasses. Its seed heads are spikes with seeds embedded in one side of the flattened stem.
Blade Characteristics
Coarse blade width (>4mm), reaching up to 10mm; blades are flat with a distinctly blunt/rounded tip; vernation is folded in the bud; ligule is a fringe of hairs; auricles are absent; collar region is constricted and light green/yellowish.
Root System
Mainly stoloniferous with roots extending from nodes; deep fibrous roots under the stolons; high thatch-forming tendency; moderate establishment speed from sod or plugs.
Growing Information
Origin Region
Native to Gulf of Mexico coasts, West Indies, and Western Africa; highly adapted to humid subtropical coastal regions
Growth Habit
Stoloniferous (spreads via thick above-ground runners); heavy mat-forming with rapid horizontal spread
Sunlight & Water Needs
Full Sun to Partial Shade (better shade tolerance than most warm-season grasses); needs 4-6 hours sun; high water needs; moderate drought tolerance but wilts quickly without water; prefers pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.5–4.0 inches; weekly frequency; fertilization 2-4 lbs N per 1000 sq ft annually; high maintenance due to water and pest needs; vertical mowing required to manage thatch.
Special Characteristics
Excellent salt tolerance (ideal for coastal areas); best shade tolerance of warm-season grasses; poor traffic/wear tolerance due to coarse fleshy stolons; susceptible to Chinch Bugs and Large Patch disease.
Ecological Information
Introduced/Naturalized in many regions; provides excellent soil stabilization in sandy coastal soils; low wildlife food value but provides cover for small invertebrates; can be invasive in sensitive wetlands.