St. Augustine Grass
Stenotaphrum secundatum · Warm-season, perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Floratam (coarser texture, blue-green color, excellent chinch bug resistance in early years)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Low cold tolerance, going dormant and turning brown with the first hard frost.
About This Grass
Forms a dense, lush, carpet-like turf with coarse-textured, flat blades. Color ranges from bright apple green to deep blue-green. Unmowed height reaches 6 to 12 inches, but typically maintained low. Produces a flat spike-like seed head at maturity.
Blade Characteristics
Blades are wide (4-10mm), flat, with blunt or rounded tips. Folded vernation in the bud. Smooth texture with prominent midrib. Ligule is a fringe of hairs, auricles are absent, and the collar is continuous.
Root System
Moderately deep fibrous root system originating from nodes on the stolons. Moderate establishment speed from sod, slower from plugs. Forms a thick thatch layer over time if over-fertilized.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and tropical regions worldwide; widely cultivated in the southern United States
Growth Habit
Aggressively stoloniferous, forming a thick, coarse, spongy mat above ground with short, robust stolons
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 water needs during active growth, moderate drought tolerance by entering dormancy.
Mowing & Maintenance
Mow at 2.5 to 3.5 inches every 7-10 days using a sharp rotary mower. Requires 2-4 lbs N per 1000 sq ft annually. High maintenance level due to regular watering, weeding, and dethatching needs.
Special Characteristics
Good shade tolerance for a warm-season grass, poor wear tolerance compared to Bermuda or Zoysia, moderate salt tolerance, susceptible to chinch bugs and take-all root rot.
Ecological Information
Introduced/naturalized in many subtropical regions. Provides excellent soil stabilization and erosion control on coastal sandy soils. Low invasive tendency outside cultivated areas, primarily spreads vegetatively via stolons.