St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Generic / Common (similar to 'Floratam' or 'Palmetto')
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F. Highly heat tolerant.
About This Grass
A coarse-textured, low-growing turfgrass that forms a dense, carpet-like sod. It is known for its vibrant medium-to-dark green color and wide, blunt blades. When unmowed, it can reach 6-12 inches; maintained, it looks lush and thick.
Blade Characteristics
Coarse blade width (8-10mm); flat shape with a distinctive rounded, boat-shaped or blunt tip. Color is a deep emerald to blue-green. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent; the collar is constricted and narrow.
Root System
Fibrous and moderately deep when well-established. Relies heavily on thick stolons for lateral spread. High thatch-forming tendency due to stolon density; establishment is relatively fast from sod or plugs.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Africa; adapted to humid tropical and subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively via above-ground runners (stolons) to form a dense, thick mat.
Sunlight & Water Needs
Full sun to moderate shade (one of the most shade-tolerant warm-season grasses). Requires at least 4-6 hours of sun. High water needs; poor drought tolerance compared to Bermuda grass; prefers well-drained fertile soils with pH 6.0-7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4.0 inches. Mowing frequency is weekly during the growing season. Fertilization: 2-4 lbs N per 1000 sq ft per year. High maintenance level due to water and pest needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear/traffic tolerance; susceptible to Chinch Bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in coastal sandy areas. Not typically considered invasive in managed landscapes but can crowd out weaker grasses. Best grown as a monostand.