St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto'
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormant straw-colored state when temperatures drop below 55°F; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, creeping grass with broad, blunt-tipped blades. It is high-density, typically bright to dark green, and produces inconspicuous spike-like seed heads on flat stems.
Blade Characteristics
Blade width >4mm (coarse); shape is flat; tip is distinctly rounded/blunt (boat-shaped/blunt); color is medium to dark green; vernation is folded; ligule is a short fringe of hairs; auricles are absent; collar is constricted.
Root System
Fibrous and relatively shallow, but supported by thick, woody stolons. Slow to establish from seed (usually sodded or plugged); moderate thatch tendency; good wear recovery via runners.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical/subtropical climates.
Growth Habit
Stoloniferous (spreads aggressively via above-ground runners), forming a thick, dense mat.
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses); needs 4-6 hours direct sun; high water requirement; moderate drought tolerance but wilts quickly without moisture; prefers slightly acidic to neutral soil (pH 6.0-7.5).
Mowing & Maintenance
Ideal height 2.5–4.0 inches; weekly frequency; fertilization 2-4 lbs N per 1000 sq ft annually; high maintenance level; prone to Chinch bugs and Gray Leaf Spot.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); poor traffic tolerance compared to Bermuda; excellent ability to crowd out weeds when healthy.
Ecological Information
Native to tropical coastal regions; provides soil stabilization for sandy coastal edges; low wildlife food value but good ground cover for small reptiles/insects; can be invasive in non-native wetland margins.