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 'Floratam' based on wide blades and purple-tinged stolons)
Hardiness Zones
USDA Zones 8-11. Excellent heat tolerance; poor cold tolerance. Becomes dormant and turns brown when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a vibrant blue-green color. It forms a thick, dense mat that effectively chokes out weeds. Unmowed, it features V-shaped or 'Y' shaped seed heads (racemes) with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat to folded, with a distinct rounded (boat-shaped) tip. Vernation is folded in the bud. Ligule is a short fringe of hairs; auricles are absent. The collar is narrow and continuous.
Root System
Moderately deep fibrous root system originating from stolon nodes. Low thatch tendency compared to Bermuda but high compared to Fescue; fast establishment via sod or plugs.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Western Africa; best in humid subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively above ground via thick, fleshy runners (stolons) to form a dense, carpet-like sod.
Sunlight & Water Needs
Partial Sun to Full Sun; one of the most shade-tolerant warm-season grasses (needs 4-6 hours). High water requirement; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
Recommended height: 2.5 to 4.0 inches. Frequency: weekly during peak growth. Fertilization: 2-4 lbs N per 1000 sq ft annually. Requires periodic aeration but rarely dethatching.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear tolerance due to fleshy stolons; susceptible to Chinch Bugs and Large Patch disease.
Ecological Information
Introduced/Naturalized in the US. Provides soil stabilization in coastal sandy soils. Limited wildlife forage value but provides cover. Can be invasive in sensitive wetland margins.