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' (most common widespread cultivar, noted for its coarse texture, blue-green color, and resistance to St. Augustine Decline virus)
Hardiness Zones
USDA Hardiness Zones 8 through 11. Extremely sensitive to cold; frost causes severe leaf damage and freezing temperatures below 20°F can kill the plant.
About This Grass
Forms a very thick, lush, coarse-textured turf. Color ranges from bright green to blue-green depending on the cultivar and fertility. Unmowed height can reach 6 to 12 inches or more, while maintained turf is kept at 2.5 to 4 inches. Produces a flattened, spike-like seed head at maturity.
Blade Characteristics
Coarse texture with wide blades (ranging from 4mm to over 10mm wide). Flat blade shape with rounded, blunt 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 on the stolons. Spreads quickly via surface stolons. Forms a spongy thatch layer relatively quickly if over-fertilized. Establishes easily from sod or plugs.
Growing Information
Origin Region
Native to tropical and subtropical regions around the Gulf of Mexico, Caribbean, and Mediterranean; widely cultivated throughout the southeastern United States, coastal California, Hawaii, and similar tropical/subtropical climates worldwide.
Growth Habit
Stoloniferous and aggressively creeping above ground, forming thick, dense mats with thick stolons (runners).
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 active growth; moderate to good drought tolerance by entering dormancy during dry spells. Prefers well-drained sandy or loam soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Mow at 2.5 to 4 inches using a rotary mower with sharp blades. Mowing frequency is every 5 to 7 days during peak growing season. High maintenance level requiring regular fertilization (2 to 4 lbs N per 1000 sq ft annually), frequent watering, and periodic dethatching.
Special Characteristics
Low to moderate traffic/wear tolerance (repairs slower than Bermuda or Zoysia). Susceptible to chinch bugs, sod webworms, take-all root rot, and brown patch. Poor cold tolerance. Excellent salt spray tolerance, making it ideal for coastal properties.
Ecological Information
Introduced and naturalized across many warm coastal regions. Provides ground cover and erosion control in coastal sandy soils. High wildlife value for local insects and small mammals finding cover within the thick turf mat. Often planted as a monoculture lawn.