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' (common southern cultivars)
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance; enters dormancy when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a characteristic deep blue-green color. It becomes dormant and turns tan in cold winters. Unmowed, it can reach 6-12 inches, but it is typically maintained as a thick sod.
Blade Characteristics
Wide blades (8-10mm), coarse texture, folded in the bud (folded vernation). The tips are distinctly rounded or blunt (boat-shaped/obtuse). Ligule is a short fringe of hairs; auricles are absent.
Root System
Moderately deep fibrous root system originating from stolon nodes; high thatch-forming tendency; slow to moderate establishment from plugs or sod (rarely grown from seed).
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Africa; thrives in tropical and subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively via thick, creeping above-ground runners (stolons) to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial Shade to Full Sun; one of the most shade-tolerant warm-season grasses. Needs frequent watering during dry spells; prefers well-drained moist soils with pH 5.0 to 8.5.
Mowing & Maintenance
Ideal height 2.5 to 4.0 inches; mow every 7-10 days; requires 2-4 lbs Nitrogen per 1000 sq ft annually; high maintenance 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 Chinch Bugs and Large Patch disease.
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in sandy coastal areas; low wildlife value in turf form; can be invasive in sensitive wetlands if escaped from lawns.