St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Floratam' (most common wide-bladed cultivar with good drought tolerance and coarse texture)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Low cold tolerance (prone to frost damage below freezing); goes dormant in cooler parts of its range.
About This Grass
Forms a dense, coarse-textured lawn with vibrant green to blue-green color. Mown height typically ranges from 2.5 to 4 inches. Unmowed, it can grow up to 6 to 12 inches tall before producing flattened seed spikes.
Blade Characteristics
Blades are coarse (5 to 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.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes quickly from sod, moderate thatch-forming tendency, moderate drought tolerance with good recovery via stolons.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, Caribbean, and Mediterranean coasts; widely cultivated throughout the southern United States.
Growth Habit
Stoloniferous, spreading aggressively via thick above-ground runners (stolons) to form a dense, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than Bermuda or Zoysia). High water needs during active growth; moderate drought tolerance entering dormancy during severe dry spells. Prefers well-drained soils with a pH of 5.5 to 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches. Mowing frequency is weekly during peak growing season. Fertilization needs are moderate to high (2 to 4 lbs N per 1000 sq ft per year). Maintenance level is medium.
Special Characteristics
Moderate wear tolerance (less than Bermuda due to spongy stolons), good salt tolerance (ideal for coastal regions), fair to good shade tolerance, excellent ability to crowd out weeds when dense and healthy.
Ecological Information
Introduced/cultivated turfgrass in many non-native regions. Provides ground cover and soil stabilization against erosion, offers limited wildlife value compared to native prairie grasses, and is commonly planted as a monoculture lawn.