St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Viridian St. Augustine
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 11. Sensitive to freezing temperatures and will go dormant and turn brown with frost. Poor cold tolerance compared to cool-season grasses.
About This Grass
Forms a dense, lush carpet with a bright to dark green color. Leaves are coarse-textured with blunt tips. When unmowed, it can grow up to 6 to 12 inches tall, but it is typically maintained at a lower height. Produces a flattened spike-like seed head.
Blade Characteristics
Coarse blade width (>4mm), flat shape with rounded or blunt tips. Color ranges from light to blue-green. Vernation is folded in the bud. Features a short membranous ligule with a fringe of hairs, continuous collar, and absent auricles.
Root System
Moderately deep fibrous root system spreading from thick stolons. High thatch-forming tendency, especially with excessive fertilization. Establishes rapidly from sod or plugs, forming a dense sod that crowds out most weeds.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, Caribbean, and Mediterranean coasts; widely cultivated throughout the southeastern United States.
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a thick, coarse turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade tolerant than most warm-season grasses). Needs regular watering (1 inch per week) and has moderate drought tolerance, entering dormancy during severe 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. High maintenance level requiring frequent mowing during the growing season, moderate to high fertilization (2 to 4 lbs N per 1000 sq ft annually), and periodic dethatching.
Special Characteristics
Moderate wear tolerance with slow recovery from heavy traffic. Good salt tolerance, making it popular for coastal properties. Moderate shade tolerance compared to other warm-season turfgrasses. Susceptible to chinch bugs, take-all root rot, and brown patch.
Ecological Information
Introduced/cultivated across southern coastal lawns. Provides good soil stabilization and erosion control on sandy coastal soils. Low wildlife forage value compared to native grasses, but forms an effective functional ground cover.