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 and insect resistance)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Highly sensitive to cold and enters winter dormancy (turning brown) in the cooler parts of its range when temperatures drop below 50 degrees Fahrenheit.
About This Grass
Forms a dense, coarse-textured, bright blue-green to dark green turf mat. When unmowed, it can reach heights of 6 to 12 inches or more, but is typically maintained at 2.5 to 4 inches. Produces flat, thick stems and a spike-like seed head at maturity.
Blade Characteristics
Coarse texture with blade width generally ranging from 4 to 10 mm. Blades are flat with rounded to slightly pointed tips, folded in the bud (vernation), with a light green to blue-green color. Features a very short membranous ligule with a fringe of hairs, continuous collar, and absent auricles.
Root System
Moderately deep fibrous root system originating from nodes along the robust stolons. Tends to build up thatch moderately fast if over-fertilized. Establishes relatively quickly from sod or plugs and forms a thick, spongy sod.
Growing Information
Origin Region
Native to tropical regions along the Gulf of Mexico, the Caribbean, and parts of the Mediterranean; widely cultivated throughout the southeastern United States and warm coastal regions globally.
Growth Habit
Stoloniferous, spreading rapidly via thick, 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 a minimum of 4 hours of direct sunlight). High water requirement during establishment and growing season; moderate drought tolerance by entering dormancy during dry spells.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower. Requires frequent mowing during the active growing season. Fertilization needs are moderate to high (2-4 lbs N per 1000 sq ft annually). Needs periodic dethatching and aeration. Maintenance level is medium-high.
Special Characteristics
Excellent shade tolerance compared to other warm-season turfgrasses, good salt tolerance making it ideal for coastal areas, moderate wear tolerance with fair recovery via stolons, and susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/cultivated widely in warm coastal regions. Provides good soil stabilization and erosion control on sandy coastal soils. Offers limited wildlife habitat due to dense managed turf monoculture, though runners provide ground cover for small ground-dwelling insects.