St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-like variety (based on coarse texture)
Hardiness Zones
USDA Zones 8-11. Poor cold tolerance; turns brown and goes dormant quickly at first frost. Does not tolerate sustained freezing temperatures well.
About This Grass
A coarse-textured, low-growing grass with a deep blue-green color. It establishes a thick sod through heavy stolons that root at the nodes. When unmowed, it can reach 6-12 inches; maintained, it creates a lush carpet. Seed heads are spike-like racemes with seeds embedded in a thick, flattened rachis.
Blade Characteristics
Coarse width (>4mm), folded vernation, blunt/rounded 'boat-shaped' or slightly rounded tips. Color is typically dark green to blue-green. The ligule is a short fringe of hairs; auricles are absent. The collar is continuous and often constricted.
Root System
Spreads primarily by stolons with a relatively shallow to moderate fibrous root system. It creates significant thatch over time but has relatively fast establishment from sod or plugs.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and West Africa. Thrives in tropical and subtropical climates.
Growth Habit
Stoloniferous (spreads via thick above-ground runners), forming a dense, coarse mat.
Sunlight & Water Needs
Requires Full Sun to Partial Shade (has better shade tolerance than most warm-season grasses). Prefers regular watering and moist, well-draining soils; moderate drought tolerance but wilts clearly under stress.
Mowing & Maintenance
Ideal height 2.5 to 4.0 inches. Requires frequent mowing to prevent thatch buildup. Fertilization 2-4 lbs N per 1000 sq ft annually. Low to medium maintenance depending on irrigation.
Special Characteristics
Excellent shade tolerance for a warm-season grass, high salt tolerance (ideal for coastal areas), moderate wear tolerance but slow to recover from heavy damage. Susceptible to Chinch bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in the US. Provides soil stabilization in coastal sandy soils. Low wildlife value in manicured lawn settings. Can be invasive in sensitive wetland margins in tropical regions.