St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely, based on leaf width and color); possibly Floratam or Palmetto depending on regional location
Hardiness Zones
USDA Zones 8-11. Poor cold tolerance; turns brown/dormant when temperatures consistently drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It forms a thick carpet that crowds out weeds. It does not produce underground rhizomes. Seed heads are short, spiked racemes with seeds embedded in a thick, flattened stem.
Blade Characteristics
Coarse blade width (8-10mm), flat shape with a rounded/obtuse tip. Vernation is folded in the bud; the ligule is a short fringe of hairs. Auricles are absent and the collar is constricted.
Root System
Moderately deep fibrous roots that emerge from nodes along the stolons. Slow to moderate establishment speed; produces significant thatch; high wear recovery but low initial traffic tolerance.
Growing Information
Origin Region
Native to tropical and subtropical regions of the Americas, Caribbean, and Africa; common in the Gulf Coast and coastal California
Growth Habit
Stoloniferous (spreads via thick, above-ground runners), forming a dense, coarse mat
Sunlight & Water Needs
Full sun to partial shade; known as one of the most shade-tolerant warm-season grasses. High water requirement to maintain green color; moderate drought tolerance but goes dormant quickly during dry periods.
Mowing & Maintenance
Ideal mowing height 2.5 to 4.0 inches. Fertilization 2-4 lbs Nitrogen/1000 sq ft/year. Requires periodic dethatching and aeration. Moderate maintenance level.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); susceptible to Chinch Bugs and Gray Leaf Spot disease.
Ecological Information
Introduced/naturalized in the US. Provides soil stabilization but can be aggressive; low wildlife value compared to native bunchgrasses; often grown in monocultures but can be mixed with clover in low-input lawns.