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 / 'Palmetto' or 'Floratam' (typical broad flat stoloniferous types)
Hardiness Zones
Thrives in USDA Hardiness Zones 8-10. Excellent heat tolerance, poor cold tolerance (susceptible to frost damage and winter dormancy when temperatures drop below freezing).
About This Grass
St. Augustine grass is a coarse-textured, aggressive warm-season turfgrass characterized by broad, flat blades, blunt tips, and thick stolons. Color ranges from light green to blue-green depending on nitrogen levels. Unmowed, it can grow 6 to 12 inches tall with upright seed stalks, but when maintained it is kept at 2.5 to 4 inches. Produces a flattened spike-like inflorescence.
Blade Characteristics
Coarse texture with wide blades typically 4-10 mm wide, flat shape, rounded or blunt tip. Vernation is folded in the bud. The collar region is continuous with a fringe of hairs representing the ligule, and auricles are absent.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes relatively quickly from sod or plugs, moderate thatch-forming tendency, forms a dense sod layer that provides good erosion control.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and tropical regions worldwide. Well-adapted to the southern United States and coastal areas.
Growth Habit
Stoloniferous, spreading rapidly by robust, thick above-ground runners (stolons) with short internodes, forming a dense, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade tolerant than most warm-season grasses, needing at least 4 hours of direct sun). High water needs to maintain lush appearance, moderate to low drought tolerance (enters dormancy during prolonged dry spells), prefers well-drained soils with a pH of 6.0 to 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower with sharp blades. High maintenance level requiring regular watering, frequent mowing during peak growing season, and fertilization of 2 to 4 lbs N per 1000 sq ft per year. Prone to thatch build-up requiring occasional dethatching.
Special Characteristics
Moderate to low wear/traffic tolerance due to spongy stolons; recovers moderately well. Susceptible to chinch bugs, sod webworms, and fungal diseases like Take-All Root Rot and Brown Patch. Good salt tolerance, making it ideal for coastal lawns.
Ecological Information
Introduced and naturalized in many warm coastal areas. Provides basic wildlife cover and soil stabilization in coastal environments. Often used as a monoculture turf and does not mix well in traditional cool-season grass blends due to its aggressive coarse growth habit.