St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely, based on the medium-green color and coarse texture visible)
Hardiness Zones
USDA Hardiness Zones 8–11. Poor cold tolerance; susceptible to winter kill in temperatures below 20°F. Enters dormancy following the first hard frost.
About This Grass
A coarse-textured, low-growing grass that forms a dense, spongy turf. It remains bright green during the growing season and turns tan/brown during winter dormancy. Unmowed, it can reach 6-12 inches; maintained, it is quite dense with thick, creeping stolons.
Blade Characteristics
Coarse width (>4mm), folded in the bud (folded vernation), rounded/obtuse tips, medium to dark green color. Blades are typically flat or folded. Ligule is a fringe of hairs; auricles are absent; collar is constricted and smooth.
Root System
Moderately deep fibrous root system originating from nodes along thick stolons. It has a high thatch-forming tendency and moderate establishment speed from sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico region, West Indies, and Western Africa; best adapted to humid subtropical and tropical climates.
Growth Habit
Stoloniferous (spreads aggressively via above-ground runners); forms a thick, carpet-like mat.
Sunlight & Water Needs
Full sun to partial shade; it is one of the most shade-tolerant warm-season grasses. Requires moderate to high watering; poor drought tolerance compared to Bermuda, as it wilts quickly without moisture.
Mowing & Maintenance
Ideal height 2.5–4.0 inches. Requires frequent mowing to prevent thatch buildup. Fertilization needs: 2–4 lbs N per 1,000 sq ft annually. 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 tolerance; susceptible to Chinch Bugs and Large Patch (Brown Patch) disease.
Ecological Information
Introduced/Naturalized in the US coastal south. Provides soil stabilization but can be invasive in non-managed sandy environments. Often grown as a monoculture; rarely mixed with other grasses due to its aggressive stolons and coarse texture.