St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Panicae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Palmetto', 'Raleigh', or 'Floratam', known for varying shade tolerance and color depth
Hardiness Zones
USDA Hardiness Zones 8 through 10, sensitive to freezing temperatures, goes dormant and turns straw-colored in cooler winter areas.
About This Grass
A coarse-textured, dense, low-growing warm-season turf grass with flat blades and a vibrant blue-green to dark green color. It spreads rapidly via long, thick stolons and produces distinctive, flat seed spikes at maturity.
Blade Characteristics
Coarse texture with wide blades (4-10mm), flat shape, rounded or blunt tips, blue-green to apple-green color, folded vernation in the bud, very short membranous ligule with a fringe of hairs, and continuous or absent auricles.
Root System
Moderate depth fibrous root system with thick stolons anchoring at nodes; high thatch-forming tendency, fast establishment from plugs or sod, moderate drought tolerance and good wear recovery through stolon expansion.
Growing Information
Origin Region
Native to tropical and subtropical coastal regions globally, well-adapted to the southern United States and Gulf Coast
Growth Habit
Aggressively stoloniferous, forming a thick, coarse, carpet-like mat via above-ground runners
Sunlight & Water Needs
Performs best in full sun but has the best shade tolerance among warm-season grasses (minimum 4 hours direct sun); high watering needs during dry spells; prefers well-draining soils with a pH of 5.5 to 7.0.
Mowing & Maintenance
Ideal mowing height of 2.5 to 3.5 inches using sharp rotary mowers, medium-high maintenance level, requires regular fertilization (2-4 lbs N per 1000 sq ft annually) and periodic dethatching due to dense thatch accumulation.
Special Characteristics
Moderate wear tolerance (lower than Bermuda or Zoysia), excellent shade tolerance, good salt tolerance making it ideal for coastal regions, susceptible to chinch bugs, take-all root rot, and brown patch.
Ecological Information
Introduced/naturalized in many subtropical regions, provides good soil stabilization and erosion control on coastal soils, forms dense turf that crowds out most weeds, but can become invasive in native tropical wetlands.