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, a popular coarse-textured cultivar known for its bright blue-green color and resistance to St. Augustine Decline (SAD) virus.
Hardiness Zones
USDA Hardiness Zones 8 through 10. Excellent heat tolerance, but poor cold tolerance (susceptible to frost damage and winter dormancy discoloration below 50°F).
About This Grass
A coarse-textured, dense, low-growing turfgrass with broad blades and a bright green to blue-green color. Mowed heights range from 2.5 to 4 inches, while unmowed growth can reach 6 to 12 inches with flattened seed spikes.
Blade Characteristics
Blades are broad (coarse, >4mm), flat, with 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 thick stolons. Forms a moderate amount of thatch, establishes quickly from sod or plugs, and provides fair wear recovery.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, the Caribbean, and coastal areas worldwide; performs best in warm, humid coastal climates.
Growth Habit
Stoloniferous, spreading aggressively by above-ground runners (stolons) to form a dense, coarse-textured turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade tolerant than most warm-season grasses, needing at least 4 hours of direct sun). High watering needs for optimal color and growth, with moderate drought tolerance by entering dormancy. Prefers well-drained 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. Requires frequent mowing during the growing season. Fertilization needs are moderate to high (2 to 4 lbs N per 1000 sq ft per year). Requires periodic dethatching and aerating due to rapid stolon production.
Special Characteristics
High salt tolerance, making it ideal for coastal areas. Moderate shade tolerance compared to other warm-season turf. Susceptible to chinch bugs, sod webworms, and large patch disease. Good weed suppression when dense.
Ecological Information
Introduced and naturalized in many coastal regions. Provides low to moderate wildlife value primarily as ground cover. Excellent for erosion control on sandy coastal soils. Often grown as a monoculture lawn.