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', a widely grown cultivar known for its coarse texture, blue-green color, and resistance to St. Augustine Decline (SAD) virus.
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Exhibits poor cold tolerance and goes dormant (turning brown) with frost. Does not tolerate heavy freezing temperatures.
About This Grass
Forms a thick, lush, light to medium green turf with a coarse texture. Unmowed height can reach 6 to 12 inches, but typically maintained at 2.5 to 4 inches. Produces a flattened spike-like seed head at maturity.
Blade Characteristics
Coarse-textured blades (typically 4-10mm wide), flat with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs. Auricles are absent. Distinctive broad collar region.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Forms a moderate to heavy thatch layer. Fast establishment from plugs or sod, providing good erosion control and soil binding.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, the Caribbean, and coastal areas worldwide. Well-adapted to warm, humid coastal climates.
Growth Habit
Stoloniferous and rhizomatous, spreading aggressively via thick, above-ground stolons (runners) to form a dense, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade tolerant than most other warm-season grasses, needing at least 4-6 hours of sun). High watering needs for optimal appearance, moderate drought tolerance entering dormancy during severe dry spells. Prefers moist, well-draining soils with a pH of 6.0 to 7.5.
Mowing & Maintenance
Mow at 2.5 to 4 inches using a rotary mower with sharp blades to prevent tearing the coarse leaves. Fertilization requires 2 to 4 lbs N per 1000 sq ft per year during the growing season. High maintenance level due to regular watering, mowing, and dethatching needs.
Special Characteristics
Moderate wear tolerance (less than Bermuda or Zoysia), poor to moderate cold tolerance, excellent shade tolerance for a warm-season grass, moderate salt spray tolerance, susceptible to chinch bugs, take-all root rot, and sod webworms.
Ecological Information
Introduced/cultivated across southern coastal regions. Provides good ground cover and soil stabilization against erosion. Valued for urban and suburban landscapes, though aggressive runners can invade flower beds.