St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4, not transition zone suitable (sensitive to cold)
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine or 'Floratam' (likely based on coarse blade width)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy below 55°F; prone to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing grass with wide, blunt leaves. It forms a thick, carpet-like sod that stays dark green in warm months but goes dormant and turns brown after the first hard frost.
Blade Characteristics
Blade width >4mm (coarse); shape is flat; tip is distinctly rounded/blunt; color is deep green to blue-green; vernation is folded in the bud; ligule is a fringe of hairs; auricles are absent; collar is constricted.
Root System
Fibrous roots originating from stolons; shallow to moderate depth; high thatch-forming tendency; slows establishment from seed (usually sodded or plugged).
Growing Information
Origin Region
Native to coastal regions of the Caribbean, Africa, and the Americas; thrives in Gulf Coast and tropical climates
Growth Habit
Stoloniferous (spreads via thick above-ground runners), forming a dense, low-growing mat
Sunlight & Water Needs
Partial sun to shade tolerant (one of the most shade-tolerant warm-season grasses); needs 4-6 hours of sun; moderate to high water needs; poor drought tolerance compared to Bermuda.
Mowing & Maintenance
Mowing height 2.5–4 inches; low to medium frequency; fertilization 2-4 lbs N per 1000 sq ft/year; high maintenance regarding water and pest monitoring.
Special Characteristics
Excellent shade tolerance; high salt tolerance (good for coastal areas); poor wear tolerance; susceptible to Large Patch (fungus) and Chinch Bugs.
Ecological Information
Introduced/naturalized in many areas; provides dense cover for soil stabilization; non-invasive in dry inland areas but can spread in moist coastal habitats.