St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Floratam
Hardiness Zones
USDA Zones 8-11. Excellent heat tolerance but poor cold tolerance; will go dormant and turn brown after the first hard frost.
About This Grass
A coarse-textured, low-growing grass that forms a thick, carpet-like turf. It is a deep blue-green color and maintains its color well into the fall. Unmowed, it can reach 6-12 inches; maintained, it is dense with thick, succulent stolons and compressed seed heads (spikes) where seeds are embedded in the rachis.
Blade Characteristics
Coarse width (>4mm), flat blades with a distinct rounded or 'boat-shaped' tip. Vernation is folded in the bud; ligule is a fringe of short hairs; auricles are absent. The leaf sheath is greatly compressed and keeled.
Root System
Fibrous and moderate depth, spreading primarily through thick, fleshy stolons. It has a high thatch-tendency due to the density of the stolons. Establishment is moderate to fast via sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico region, West Indies, and Western Africa; commonly cultivated in the Southern United States and subtropical regions.
Growth Habit
Stoloniferous (spreads via above-ground runners), forming a dense, thick, mat-building sod.
Sunlight & Water Needs
Partial sun to full sun (4-6 hours minimum); among the most shade-tolerant of warm-season grasses. Requires moderate to high watering; low drought tolerance compared to Bermuda grass; thrives in moist, well-drained soils with pH 5.0-8.5.
Mowing & Maintenance
Mowing height: 3.5 to 4.0 inches. Frequency: weekly during growing season. Fertilization: 2-4 lbs N per 1000 sq ft annually. Requires periodic dethatching and aeration; high maintenance level.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (coastal suitable); poor wear/traffic tolerance due to thick stolons being easily crushed; susceptible to Chinch bugs and Large Patch (brown patch) disease.
Ecological Information
Introduced/Naturalized in many regions; provides high soil stabilization and erosion control; low wildlife food value but provides cover; can be invasive in non-native wetland margins; often grown as a monostand but can be mixed with clover in low-input areas.