St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Commonly 'Palmetto', 'Floratam', or 'Raleigh', known for shade tolerance or color retention
Hardiness Zones
USDA Hardiness Zones 8-10. Low cold tolerance, goes dormant and discolors with frost, susceptible to freeze damage below 20°F.
About This Grass
Forms a lush, dense, blue-green to dark green turf with broad, flat blades. Typically maintained at heights between 2.5 to 4 inches. Unmowed, it can grow up to 6-12 inches tall with flattened, thick stems and a spike-like seed head.
Blade Characteristics
Coarse texture, width typically 4-10mm. Blades are flat with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs. Auricles are absent. Smooth texture with prominent midrib.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Forms a spongy thatch layer quickly. Moderate establishment speed from sod or plugs.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and tropical regions worldwide
Growth Habit
Stoloniferous, spreading aggressively via thick above-ground runners (stolons) to form a dense, coarse turf mat
Sunlight & Water Needs
Requires full sun to partial shade (more shade tolerant than many warm-season grasses). High water needs during active growth and establishment. Moderate drought tolerance, enters dormancy during severe drought.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower. High maintenance level requiring regular fertilization, frequent watering, and periodic dethatching due to rapid stolon production.
Special Characteristics
Good shade tolerance and moderate salt tolerance, making it popular in coastal areas. Poor heavy-traffic wear tolerance compared to Bermuda or Zoysia. Susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/naturalized in many subtropical regions. Provides excellent soil stabilization and erosion control in coastal sandy soils. Low wildlife forage value compared to native grasses.