St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial (C4)
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on blade width and growth density
Hardiness Zones
USDA Hardiness Zones 8-10; poor cold tolerance, goes dormant and turns tan/brown after a hard frost; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, creeping grass that creates a thick, lush green carpet. It has a medium-to-dark green color and stays green longer into the fall than many other warm-season grasses. Seed heads are spike-like racemes but rarely produce viable seeds in managed lawns.
Blade Characteristics
Wide blades (8-10mm), coarse texture, folded vernation, rounded or boat-shaped tips. Ligule is a fringe of hairs; auricles are absent. The collar is narrowed and often a lighter shade of green.
Root System
Fibrous and relatively shallow, though stolons provide massive horizontal spread. Fast establishment via sod or plugs; moderate-to-high thatch-forming tendency.
Growing Information
Origin Region
Native to coastal regions of the Caribbean, Gulf of Mexico, Mediterranean, and Western Africa; best in tropical and subtropical climates
Growth Habit
Stoloniferous (spreads via thick above-ground runners), forming a dense, coarse mat
Sunlight & Water Needs
Partial sun to full sun; exhibits the best shade tolerance among warm-season grasses (needs at least 4-5 hours of light). Requires regular watering; moderate drought tolerance but wilt-sensitive.
Mowing & Maintenance
High maintenance. Ideal mowing height of 2.5 to 4.0 inches; requires frequent fertilization during growing season (2-4 lbs N/1000 sq ft/yr) and periodic dethatching.
Special Characteristics
Excellent shade tolerance for a warm-season grass, high salt tolerance (ideal for coastal areas), moderate wear tolerance, but susceptible to Chinch Bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in many southern US states; provides excellent soil stabilization for sandy coastal soils; generally non-invasive in non-tropical environments due to cold sensitivity.