St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Floratam' (broad, coarse blades with blue-green color)
Hardiness Zones
USDA Hardiness Zones 8 through 10, with some cultivars extending into warm microclimates of Zone 7. Excellent heat tolerance, poor cold tolerance (susceptible to frost damage and winter dormancy discoloration below 50°F).
About This Grass
Forms a lush, dense, blue-green to dark green turf with a coarse texture. Unmowed height reaches 6 to 12 inches, but typically maintained at 2.5 to 4 inches. Produces flat seed spikes.
Blade Characteristics
Coarse width (greater than 4mm), flat shape with rounded tips, bright to blue-green color, rolled in the bud (vernation), smooth texture with prominent midveins. Short membranous ligule with a fringe of hairs, clasping auricles absent, continuous collar.
Root System
Moderately deep fibrous root system originating from nodes along the thick stolons. Forms a moderate to heavy thatch layer. Establishes rapidly from sod, moderately from plugs.
Growing Information
Origin Region
Native to tropical and subtropical coastal regions globally; widely cultivated in the southeastern United States, Gulf Coast, and parts of the Southwest and California.
Growth Habit
Stoloniferous; spreads aggressively above ground via thick stolons (runners) to form a dense, coarse-textured turf mat.
Sunlight & Water Needs
Performs best in full sun, but has the highest shade tolerance among warm-season turfgrasses (requires at least 4 hours of direct sun). High water needs during active growth, moderate drought tolerance (enters dormancy during severe drought). Prefers well-drained soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower. Frequency is weekly during active summer growth. Requires 2 to 4 lbs N per 1000 sq ft annually. Medium-high maintenance level, requiring regular watering, dethatching, and weed control.
Special Characteristics
Moderate wear tolerance (lower than Bermuda or Zoysia), poor traffic recovery without stolons, susceptible to chinch bugs and take-all root rot, good salt spray tolerance, excellent shade tolerance for a warm-season grass, poor winter color retention in cooler zones.
Ecological Information
Introduced/cultivated turfgrass in many areas. Provides good soil stabilization and erosion control on coastal sandy soils due to its dense mat. Low invasive tendency outside of cultivated landscapes, but can escape into moist tropical habitats.