St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Floratam
Hardiness Zones
USDA Hardiness Zones 8 through 10. Excellent heat tolerance, but poor cold tolerance (susceptible to frost damage and winter kill below 25°F).
About This Grass
Forms a dense, coarse-textured, blue-green to dark green turf mat. Leaf blades are relatively wide with blunt tips. Unmowed height can reach 6 to 12 inches, but typically maintained at 2.5 to 4 inches. Produces flattened seed stalks with spike-like racemes.
Blade Characteristics
Coarse texture, blade width typically 4-10 mm, flat shape with rounded or blunt tips. Rolled vernation in the bud. Distinctive prominent midvein. Ligule is a fringe of hairs. Auricles are absent. Broad collar region.
Root System
Moderate root depth with a fibrous root system anchored by vigorous surface stolons. Moderate to high thatch-forming tendency, especially with excess nitrogen. Establishes rapidly from sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of the southeastern United States, and the Caribbean. Thrives in tropical and subtropical climates worldwide.
Growth Habit
Stoloniferous, spreading aggressively by thick, flat above-ground runners (stolons) to form a dense, coarse-textured turf mat.
Sunlight & Water Needs
Performs best in full sun, but is the most shade-tolerant warm-season grass, requiring a minimum of 4 hours of direct sunlight. Moderate to high watering needs; moderate drought tolerance by entering dormancy during dry spells. Prefers moist, well-draining soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches using a rotary mower. High mowing height is essential for shade tolerance and deep roots. Fertilization schedule of 2-4 lbs N per 1000 sq ft per year. High maintenance level due to thatch control, pest susceptibility, and frequent mowing.
Special Characteristics
Moderate wear tolerance; slower to recover from traffic compared to Bermuda or Zoysia. Susceptible to chinch bugs, sod webworms, and large patch disease. Good salt spray tolerance, making it ideal for coastal properties. Fair shade tolerance compared to other warm-season grasses.
Ecological Information
Introduced and widely cultivated in coastal tropical and subtropical regions. Provides moderate wildlife habitat and excellent soil stabilization and erosion control in coastal sandy soils. Can crowd out weeds when managed densely, but susceptible to weed invasion if thinned out.