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 commercial variety, known for its coarse texture and purple stolon stems)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Low cold tolerance, going dormant and turning brown with the first heavy frost. Not suitable for transition zones with harsh winters.
About This Grass
Forms a dense, thick, carpet-like turf with coarse-textured, flat blades. Color ranges from light green to blue-green depending on fertilization. Mows well to a height of 2.5 to 4 inches, but can grow much taller if left unmaintained. Produces a flat spike-like seed head.
Blade Characteristics
Blades are coarse (>4mm wide), flat, with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs. Auricles are absent. The collar region is continuous and broad.
Root System
Moderately deep fibrous root system combined with robust surface stolons. Tends to build up thatch moderately fast. Fast establishment from sod, moderate from plugs; poor establishment from seed as it is rarely grown from seed.
Growing Information
Origin Region
Native to the Gulf of Mexico region, the Caribbean, and tropical coasts worldwide; well-adapted to the southern United States and tropical climates.
Growth Habit
Aggressively stoloniferous, spreading via thick, above-ground runners (stolons) to form a dense, coarse-textured turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). Moderate to high watering needs; moderate drought tolerance by entering dormancy during severe dry spells, but prefers consistently moist soils.
Mowing & Maintenance
Mow at 2.5 to 4 inches high. High mowing height is critical for health. Medium to high maintenance level requiring regular fertilization, watering, and occasional dethatching.
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance (making it popular in coastal areas), low wear tolerance compared to Bermuda or Zoysia, and susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/naturalized in many tropical and subtropical regions. Provides ground cover and soil stabilization against erosion in coastal environments. Low invasive risk outside of managed landscapes.