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 purple stolons)
Hardiness Zones
USDA Hardiness Zones 8 through 10. Very sensitive to cold weather and freezes, entering winter dormancy and turning brown in cooler limits of its range.
About This Grass
A coarse-textured, dense, bright green to blue-green warm-season turfgrass. Forms a lush, dense carpet when well-maintained. Height can reach several inches if unmoved, but maintained at 2.5 to 4 inches. Produces flat, flattened seed spikes at maturity.
Blade Characteristics
Blades are coarse, flat, wide (typically 4-10mm), with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs, and auricles are absent. The collar is continuous and broad.
Root System
Moderately deep fibrous root system originating from nodes on the stolons. Forms a moderate to heavy thatch layer. Establishes rapidly from sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of tropical and subtropical regions worldwide. Thrives in warm, humid coastal climates.
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a thick, coarse-textured turf mat.
Sunlight & Water Needs
Requires full sun to moderate shade (more shade tolerant than most warm-season grasses). High water requirement for optimal appearance, moderate drought tolerance by entering dormancy during dry spells. Prefers moist, well-draining soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Mow at 2.5 to 4 inches high using a sharp rotary mower to prevent tearing the wide blades. High maintenance level requiring regular irrigation, fertilization (2-4 lbs N per 1000 sq ft annually), and periodic dethatching.
Special Characteristics
Low to moderate wear tolerance compared to Bermuda or Zoysia; poor cold tolerance; moderate to good salt tolerance making it ideal for coastal lawns; good shade tolerance for a warm-season grass; susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/naturalized in many subtropical regions outside its native range. Provides good soil stabilization and erosion control in coastal sandy soils. Low invasive weed suppression if turf thins out.