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' (most common wide-bladed cultivar, highly popular in Florida and the Gulf Coast)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Susceptible to freeze damage below 25°F (-4°C), going into winter dormancy in the northern ranges of its adaptability.
About This Grass
Forms a dense, coarse-textured, bright to blue-green turf mat. Unmowed height can reach 6 to 12 inches, but it is typically maintained at 2.5 to 4 inches. The seed head is a flattened, unilateral spike with spikelets embedded alternately along a zigzag axis.
Blade Characteristics
Blades are coarse (typically 4-10 mm wide), flat, with blunt, rounded tips. Vernation is folded in the bud. Ligule is a fringe of hairs. Auricles are absent. The collar region is continuous and broad, often whitish.
Root System
Moderate depth fibrous root system with thick, branching stolons that creep across the soil surface. Establishes rapidly from sod, has a moderate to high thatch-tendency, and creates a very dense turf canopy that resists weed invasion.
Growing Information
Origin Region
Native to tropical regions along the Gulf of Mexico, Caribbean, and Mediterranean; widely cultivated throughout the southeastern and coastal United States, parts of Australia, and South Africa. Performs best in warm, humid coastal climates.
Growth Habit
Stoloniferous (spreading aggressively above ground via runners or stolons), forming a thick, coarse, carpet-like sod.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most other warm-season grasses, needing at least 4 hours of direct sunlight). Watering needs are high; moderate to low drought tolerance, entering dormancy or wilting quickly under prolonged dry spells. Prefers moist, fertile soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower with sharp blades. Mowing frequency is weekly during the active growing season. Requires 2 to 4 lbs of nitrogen per 1000 sq ft annually. Medium-high maintenance level.
Special Characteristics
Moderate traffic and wear tolerance (slower to recover from heavy damage due to stoloniferous growth compared to Bermuda). Good salt tolerance, making it ideal for coastal properties. Moderate shade tolerance. Prone to chinch bugs, take-all root rot, and large patch disease.
Ecological Information
Introduced and naturalized in many coastal subtropical regions. Provides soil stabilization and erosion control in sandy coastal soils. Valued for urban and suburban green spaces, offering a dense ground cover that filters runoff. Can occasionally become weedy or invasive in natural tropical wetlands.