St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam', 'Palmetto', or 'Raleigh' based on blade width and color
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enter dormancy/turns light tan when temperatures drop below 55°F; very heat tolerant.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy sod. Leaves are typically deep green to blue-green, remaining emerald if well-watered. Seed heads are inconspicuous, appearing as short, thick spikes (spikes embedded in an enlarged rachis).
Blade Characteristics
Coarse width (8-10mm); flat shape with a distinct folded vernation; broad, rounded/blunt boat-shaped tips; edges usually smooth; ligule is a short fringe of hairs; auricles are absent; collar is broad and conspicuous.
Root System
Moderately deep fibrous root system; high thatch-forming tendency due to heavy stolon production; quick establishment from sod or plugs; excellent wear recovery once established.
Growing Information
Origin Region
Native to coastal regions of West Africa, Caribbean, and Gulf Coast; best in humid subtropical climates
Growth Habit
Stoloniferous; spreads aggressively via thick above-ground runners to form a dense, thick mat
Sunlight & Water Needs
Partial Shade to Full Sun; 4-6 hours minimum; high water needs (1-1.5 inches per week); moderate drought tolerance but wilt-sensitive; prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.5-4.0 inches; weekly frequency; fertilization 2-4 lbs N per 1000 sq ft/year; high maintenance regarding dethatching and water tracking.
Special Characteristics
Excellent shade tolerance compared to other warm-season grasses; high salt tolerance (good for coastal areas); poor traffic tolerance compared to Bermuda.
Ecological Information
Introduced/Naturalized in USA; provides dense ground cover for soil stabilization; prone to Chinch bugs and Gray Leaf Spot; often used alone rather than in mixes due to its aggressive growth habit.