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 cultivars showing wide, coarse blades and purple-tinged stolons)
Hardiness Zones
USDA Hardiness Zones 8-11. Excellent heat tolerance; poor cold tolerance. Enters brown dormancy when temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing turfgrass with a creeping habit. It is known for its wide blades and thick stolons. In unmowed states, it can reach 6-12 inches but is typically maintained low. It maintains a deep blue-green color until the first hard frost.
Blade Characteristics
Blade width is coarse (>4mm), shape is flat, with a distinct rounded/obtuse boat-shaped tip. Vernation is folded in the bud. Color is medium to dark green. The ligule is a short fringe of hairs; auricles are absent; the collar is continuous and narrowed.
Root System
Moderately deep fibrous root system originating from stolon nodes. It forms heavy thatch and has a moderate to fast establishment speed in optimal heat.
Growing Information
Origin Region
Native to the Gulf of Mexico, Caribbean, and Western Africa; highly adapted to coastal regions and the Southern US
Growth Habit
Stoloniferous (spreads aggressively via thick above-ground runners); forms a dense, coarse mat
Sunlight & Water Needs
Full sun to partial shade; it is one of the most shade-tolerant warm-season grasses. High water requirements; poor drought tolerance compared to Bermuda, prefers moist, well-drained soils with pH 5.0-8.5.
Mowing & Maintenance
Mowing height 2.5–4.0 inches. Frequency: weekly during peak growth. Fertilization: 2-4 lbs N/1000 sq ft/year. High maintenance level due to water and pest needs.
Special Characteristics
Exceptional shade tolerance for a warm-season grass; high salt tolerance (excellent for coastal areas); poor wear tolerance; susceptible to Chinch Bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in many regions; provides good soil stabilization against erosion; can be invasive in non-native tropical wetlands; often grown as a monoculture but can coexist with Centipede grass in some regions.