St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' (Commonly cultivated large-bladed varieties)
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing grass with a creeping habit. It is characterized by thick, succulent stolons and a deep green to blue-green color. It forms a dense sod that crowds out most weeds but has a distinctively wide blade compared to other turf grasses.
Blade Characteristics
Coarse blade width (8-10mm); blades are flat and wide with a distinctive rounded/blunt tip; vernation is folded in the bud; ligule is a short fringe of hairs; auricles are absent; color is typically medium to dark green.
Root System
Moderately deep fibrous root system; high thatch-tendency due to thick stolons; relatively fast establishment from sod or plugs but does not produce viable seeds for retail.
Growing Information
Origin Region
Coastal areas of the Gulf of Mexico, Caribbean, and West Africa; adapted to tropical and subtropical humid regions
Growth Habit
Stoloniferous; spreads via thick, above-ground runners (stolons) to form a dense, coarse-textured mat
Sunlight & Water Needs
Partial sun to full sun (one of the most shade-tolerant warm-season grasses); requires regular moisture; moderate drought tolerance but wilt-prone during extreme heat without irrigation; prefers slightly acidic to neutral soil (pH 6.0-7.5).
Mowing & Maintenance
Recommended mowing height of 3.0 to 4.0 inches; requires frequent mowing during peak summer; fertilization of 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 due to succulent stolons; susceptible to Large Patch (fungus) and Chinch bugs.
Ecological Information
Introduced/Naturalized in the Southern US; provides soil stabilization in sandy coastal areas; low wildlife value in mowed turf form; can be aggressive in optimal climates but rarely considered invasive in non-wetland terrestrial settings.