St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass, Coastal Turf
Variety / Cultivar
'Floratam' (most common wide-bladed cultivar with good drought and insect tolerance)
Hardiness Zones
USDA Hardiness Zones 8 through 10. Excellent heat tolerance, poor cold tolerance (goes dormant and can suffer winter kill below freezing temperatures).
About This Grass
Forms a lush, dense, blue-green to green carpet with coarse-textured leaves. Grows quickly in warm weather, reaching heights of 3 to 4 inches if unmanaged, but typically maintained around 2.5 to 4 inches. Produces flat, upright seed spikes at maturity.
Blade Characteristics
Coarse blades (>4mm wide), flat shape with rounded tips, blue-green or dark green color, folded in the bud (vernation), short membranous ligule with a fringe of hairs, continuous collar, and absent auricles.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes relatively quickly from sod, forms a dense sod, and has a moderate to high thatch-forming tendency.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, Caribbean, and Mediterranean; widely cultivated in the southeastern United States
Growth Habit
Stoloniferous (spreads aggressively via above-ground runners called stolons) forming a thick, coarse turf mat
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than most warm-season grasses). High water needs during active growth, moderate drought tolerance entering dormancy during severe dry spells. Prefers well-drained soils with a pH of 5.5 to 7.0.
Mowing & Maintenance
Mow at 2.5 to 4 inches high using a sharp rotary mower. Moderate to high fertilization needs (2 to 4 lbs N per 1000 sq ft annually). Requires regular dethatching and occasional aeration. High maintenance level.
Special Characteristics
Good shade tolerance compared to other warm-season grasses, moderate salt tolerance (ideal for coastal areas), poor wear/traffic tolerance due to spongy stolon network, prone to chinch bugs and large patch disease.
Ecological Information
Introduced/naturalized in many tropical regions outside its native range. Provides good soil stabilization and erosion control on coastal sandy soils. Low wildlife grazing value compared to native grasses.