St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Exhibits poor cold tolerance and will suffer freeze damage below 25°F (-4°C). Highly popular in tropical and subtropical regions, especially in the southern US.
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Variety / Cultivar
Floratam (most common coarse-textured cultivar with blue-green leaves and good disease resistance)
About This Grass
St. Augustine grass is a coarse-textured, high-maintenance warm-season turfgrass known for its blue-green to dark green coloration. It forms a dense, carpet-like sod when properly managed. Unmowed, it can grow up to 6 to 12 inches tall with upright seed heads, but it is typically maintained at a height of 2.5 to 4 inches. It goes dormant and turns straw-brown in cooler winter months.
Blade Characteristics
Blades are coarse (greater than 4mm wide), flat, with rounded tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar region is continuous and broad, often pale-colored.
Root System
Moderately deep fibrous root system originating from the nodes of stolons. Forms a moderate to high amount of thatch. Establishment speed is moderate to fast from sod or plugs. Offers moderate drought tolerance and good recovery via stolons.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of the southeastern United States, the Caribbean, and tropical regions worldwide. Thrives in warm, humid coastal climates.
Growth Habit
Stoloniferous, producing thick, flat above-ground runners that spread rapidly and form a coarse, dense turf mat.
Sunlight & Water Needs
Requires full sun to partial shade; it is the most shade-tolerant warm-season turfgrass. Requires regular watering (approx. 1 inch of water per week) and has moderate drought tolerance, entering dormancy during severe dry spells. Prefers well-draining 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 to avoid tearing the wide blades. Mowing frequency is weekly during the active growing season. Fertilization needs are moderate to high (2 to 5 lbs N per 1000 sq ft per year). Requires periodic dethatching and core aeration. Maintenance level is medium-high.
Special Characteristics
Fair traffic and wear tolerance compared to Bermuda or Zoysia, but recovers well from damage via rapid stolon growth. Excellent salt tolerance, making it ideal for coastal properties. Moderate to good shade tolerance. Susceptible to chinch bugs, sod webworms, and fungal diseases like take-all root rot and brown patch.
Ecological Information
Introduced and widely cultivated in coastal residential and commercial landscapes. Provides good soil stabilization and erosion control on sandy coastal soils. Wildlife habitat value is minimal in manicured lawns, though it can provide cover for small ground insects and invertebrates. Usually established as a monoculture sod.