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' (most common wide-bladed cultivar with good drought tolerance and lighter green color)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Poor cold tolerance, goes dormant and turns brown when temperatures drop below 50°F, susceptible to freeze damage below freezing. Excellent heat tolerance.
About This Grass
Forms a dense, coarse-textured turf with flat, broad blades and blunt tips. Color ranges from light to dark blue-green depending on the cultivar. Grows rapidly in hot weather, reaching heights of 3 to 4 inches if unmowed, but maintained as a low-growing lawn between 2.5 and 4 inches. Produces flattened seed spikes.
Blade Characteristics
Blades are coarse (>4mm wide, typically 6-10mm), flat with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs. Auricles are absent. The collar is continuous and broad.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes quickly from sod or plugs. Prone to thatch accumulation under high nitrogen and moisture conditions. Forms a very dense, spongy sod.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of the southeastern United States, the Caribbean, and tropical regions worldwide. Thrives in humid subtropical and tropical climates.
Growth Habit
Stoloniferous (spreading aggressively via thick, above-ground runners called stolons) forming a dense, coarse-textured turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses requiring a minimum of 4 hours of direct sun). High water requirement, especially during establishment and hot dry spells; moderate drought tolerance by entering dormancy.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower with sharp blades to prevent tearing the coarse leaves. Fertilization needs are moderate to high (2 to 5 lbs N per 1000 sq ft per year). Regular dethatching and core aeration needed for heavy soils. Maintenance level is medium.
Special Characteristics
Good shade tolerance compared to other warm-season grasses. Moderate traffic tolerance but slow to recover from severe damage due to coarse stoloniferous growth. Susceptible to chinch bugs, take-all root rot, and St. Augustine decline virus. Moderate salt tolerance.
Ecological Information
Introduced and naturalized widely in warm coastal regions. Excellent for soil stabilization and erosion control in sandy coastal soils. Provides limited wildlife habitat. Often grown as a monoculture due to its aggressive stoloniferous habit.