St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass and Coastal Erosion Control
Variety / Cultivar
'Palmetto', 'Floratam', or 'CitraBlue' (Common warm-season turf cultivars with varying shade tolerance and color)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10; has poor cold tolerance and goes dormant with a brown color when temperatures drop below freezing
About This Grass
Forms a thick, carpet-like turf with coarse-textured, flat blades. Color ranges from medium to dark bluish-green. Height when unmaintained can reach 6 to 12 inches, but typically maintained at 2.5 to 4 inches. Produces a flattened spike inflorescence at maturity.
Blade Characteristics
Coarse texture with wide blades (typically 4 to 10 mm wide), flat shape, blunt or rounded tips, folded vernation in the bud, prominent ligule modified into a fringe of hairs, and absent auricles
Root System
Shallow to moderately deep fibrous root system originating from nodes on the stolons; moderate establishment speed from sod or plugs; forms a dense sod but can be prone to thatch buildup
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and tropical regions worldwide; widely cultivated in the southeastern United States and warm coastal areas globally
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a dense, coarse-textured turf mat
Sunlight & Water Needs
Performs best in full sun, but is notably the most shade-tolerant warm-season grass; requires regular watering and has moderate to high moisture needs; moderate drought tolerance by entering dormancy during severe dry spells
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower; requires moderate to high maintenance including regular fertilization (2 to 4 lbs N per 1000 sq ft per year), frequent irrigation, and occasional dethatching
Special Characteristics
Good shade tolerance for a warm-season grass, moderate salt tolerance making it ideal for coastal areas, fair wear tolerance but slower to recover from severe damage compared to Bermuda grass; susceptible to chinch bugs and take-all root rot
Ecological Information
Introduced and naturalized in many tropical and subtropical regions; provides good soil stabilization and erosion control in coastal sandy soils; offers limited wildlife habitat compared to native prairie grasses