St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-like; distinguished by coarse texture and broad blades.
Hardiness Zones
USDA Zones 8-11. Excellent heat tolerance; poor cold tolerance; goes dormant and turns brown when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing turfgrass with a medium to dark green color. It forms a thick sod through aggressive stolons. When unmowed, it can reached 6-12 inches; maintained, it looks lush and dense. Seed heads are spike-like racemes with seeds embedded in a thick rachis.
Blade Characteristics
Coarse width (>4mm), flat shape with a distinct boat-shaped or rounded tip. Color is typically medium to dark green. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent. The collar is continuous and somewhat constricted.
Root System
Fibrous, moderately deep root system developed from nodes along the stolons. Slow to moderate establishment speed; forms a heavy thatch layer over time. Good wear recovery due to stoloniferous growth.
Growing Information
Origin Region
Coastal regions of Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical and subtropical climates.
Growth Habit
Stoloniferous (spreads via thick, above-ground runners); forms a dense, carpet-like mat.
Sunlight & Water Needs
Partial sun to full sun (one of the most shade-tolerant warm-season grasses); needs minimum 4-6 hours of sun. High water needs; poor drought tolerance compared to Bermuda grass; prefers moist, well-drained soils with pH 6.0-7.5.
Mowing & Maintenance
Height: 2.5–4.0 inches. Frequency: weekly during peak growth. Fertilization: 2-4 lbs N per 1000 sq ft annually. High maintenance level; requires regular dethatching and is sensitive to certain herbicides.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); susceptible to Large Patch (fungus) and Chinch bugs; low traffic tolerance compared to Bermuda.
Ecological Information
Native to coastal areas of Americas and Africa. Provides soil stabilization in sandy coastal soils. Not typically considered invasive in managed landscapes but can crowd out native species in sensitive wetlands.