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 widely used cultivar known for its coarse texture, blue-green color, and resistance to St. Augustine Decline (SAD) virus.
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Low cold tolerance; goes completely dormant and turns brown when temperatures drop below freezing for extended periods.
About This Grass
Forms a dense, coarse-textured, blue-green to dark green turf mat. When unmowed, it can grow up to 6 to 12 inches tall, but it is typically maintained lower. Produces flat, upright seed heads on terminal spikes at maturity.
Blade Characteristics
Blades are coarse (typically 4-10 mm wide), flat with blunt or rounded tips, folded in the bud (vernation), with a prominent midvein. Ligule is a fringe of hairs, and auricles are absent.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Forms a thick layer of thatch if not managed properly. Establishes relatively quickly from sod or plugs.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, the Caribbean, and along the Mediterranean. Cultivated extensively in warm, humid coastal regions worldwide, particularly the southern United States.
Growth Habit
Stoloniferous, spreading rapidly 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 most warm-season grasses, needing at least 4 hours of direct sunlight). High water needs during active growth, with moderate to low drought tolerance (enters dormancy during severe drought). Prefers moist, well-draining soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Mow at a height of 2.5 to 4 inches every 7-10 days during the growing season. High maintenance requirement, needing regular fertilization (2-5 lbs N per 1000 sq ft annually), frequent watering, and periodic dethatching.
Special Characteristics
Moderate wear tolerance (poor recovery compared to Bermuda or Zoysia), poor cold tolerance, excellent salt tolerance (ideal for coastal areas), fair shade tolerance compared to other warm-season grasses.
Ecological Information
Introduced and naturalized in many tropical and subtropical regions. Provides soil stabilization and erosion control in coastal sandy soils. Low wildlife forage value, primarily used for residential lawns, commercial landscapes, and coastal stabilization.