St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on the coarse blade width and common residential use; 'Floratam' is distinguished by its purple-tinted stolons and lack of cold hardiness.
Hardiness Zones
USDA Hardiness Zones 8-11. It has poor cold tolerance and will go dormant and turn brown after the first hard frost. It is highly susceptible to winter kill in temperatures below 20°F.
About This Grass
A coarse-textured, low-growing turfgrass with a deep green to blue-green color. It forms a thick, spongy carpet. Seed heads are spike-like racemes but are often sterile in cultivated varieties and rarely prominent in maintained lawns.
Blade Characteristics
Coarse blade width (8-10mm), flat shape with a distinctively rounded or 'boat-shaped' tip, and folded vernation. The ligule is a short fringe of hairs; auricles are absent. The collar is continuous and somewhat constricted.
Root System
Fibrous root system arising from stolon nodes. It has a moderate root depth and a high tendency to form a thick thatch layer. Establishment is relatively fast from sod or plugs but slow from seed (which is rarely available).
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, the Caribbean, and West Africa. Widely adapted to humid subtropical and tropical regions.
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners), forming a dense, coarse-textured mat. It does not produce underground rhizomes.
Sunlight & Water Needs
Partial sun to full sun (requires at least 4-6 hours of light). It is one of the most shade-tolerant warm-season grasses. Requires moderate to high watering; has poor drought tolerance compared to Bermuda grass and will wilt quickly without moisture.
Mowing & Maintenance
Ideal height is 2.5 to 4.0 inches. Mowing frequency is weekly during the growing season. Fertilization requires 2-4 lbs of Nitrogen per 1000 sq ft annually. High maintenance level due to water and dethatching needs.
Special Characteristics
Excellent salt tolerance (ideal for coastal properties), moderate wear tolerance, and high shade tolerance for a warm-season grass. Susceptible to Large Patch (fungus) and Chinch Bugs.
Ecological Information
Introduced/Naturalized in the US. Provides habitat for small invertebrates but can be monocultural. Used for soil stabilization in sandy coastal soils. Often grown as a pure stand rather than in seed blends.