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 good resistance to the St. Augustine decline virus.
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Exceptional heat tolerance, but poor cold tolerance (susceptible to frost damage and enters winter dormancy below 50°F).
About This Grass
Forms a thick, lush, carpet-like turf with coarse-textured, flat blades. Color ranges from bright apple green to deep blue-green. Unmowed height can reach 6 to 12 inches, but typically maintained at 2.5 to 4 inches. Produces a flattened spike-like seed head at maturity.
Blade Characteristics
Blades are coarse (over 4mm 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 narrow.
Root System
Moderate-depth fibrous root system with aggressive surface stolons. Moderate to high thatch-forming tendency, especially with excessive fertilization. Establishes rapidly from sod or plugs.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, the Caribbean, and coastal areas worldwide. Well-adapted to the southern United States and coastal regions.
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, requiring at least 4 hours of direct sun). High water needs for best appearance, moderate drought tolerance by entering dormancy during severe dry spells. Prefers moist, well-draining 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 with sharp blades to prevent tearing the coarse leaves. Mowing frequency is weekly during the active growing season. Fertilization requires 2 to 4 lbs N per 1000 sq ft per year. High maintenance level due to susceptibility to pests and watering needs.
Special Characteristics
Moderate to good shade tolerance compared to other warm-season turfgrasses. Moderate wear tolerance, but slower recovery from traffic than Bermuda grass. Low salt tolerance makes it ideal for coastal properties. Susceptible to chinch bugs, take-all root rot, and brown patch.
Ecological Information
Introduced and widely cultivated in southern residential landscapes. Provides good soil stabilization and erosion control on coastal sandy soils. Low invasive potential outside of managed landscapes, though can spread into adjacent natural areas in tropical climates.