St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Highly sensitive to frost and freezing temperatures, entering dormancy when temperatures drop.
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Variety / Cultivar
Common St. Augustine / 'Floratam'
About This Grass
Forms a dense, carpet-like turf with coarse, broad blades. Typically maintained at 2.5 to 3 inches. Exhibits a bright blue-green to dark green color depending on fertility and moisture. Goes dormant and turns brown during cool winters in the northern limits of its range.
Blade Characteristics
Coarse texture with wide blades typically measuring 4 to 10 mm in width. Blades are flat with rounded tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar region is continuous and broad.
Root System
Moderate to deep root system anchored by strong stolons. Establishes relatively quickly from sod or plugs. Forms a thick thatch layer over time if not managed properly. Good drought tolerance through dormancy, but poor cold tolerance.
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 regions.
Growth Habit
Aggressively stoloniferous, forming a thick, coarse-textured turf mat by spreading via flat above-ground runners (stolons).
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). Needs moderate to high watering during growing season. Prefers moist, fertile soils with a pH between 5.5 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower to avoid tearing wide blades. Requires moderate to high maintenance, including regular fertilization (3-5 lbs N per 1000 sq ft annually) and periodic dethatching.
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance making it popular in coastal areas, excellent weed-crowding ability when healthy, but low traffic and wear tolerance compared to Bermuda or Zoysia.
Ecological Information
Introduced to many regions for turf use. Provides good soil stabilization and erosion control in coastal sandy soils. Low wildlife value compared to native prairie grasses, but offers ground cover and micro-habitats in suburban landscapes.