St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely 'Floratam' or 'Palmetto' based on coarse blade structure and growth pattern)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy below 55°F; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing grass with wide blades and creeping stems. It maintains a medium-to-dark green color in warm months and turns brown after the first hard frost. Seed heads are spike-like racemes with seeds embedded in a thick rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat to folded, with a distinct rounded/obtuse tip. Color is bright green to blue-green. Vernation is folded. Ligule is a fringe of short hairs; auricles are absent; the collar is continuous and narrowed.
Root System
Moderately deep fibrous roots originating from stolon nodes; high thatch-forming tendency; establishes via sod or plugs rather than seed; excellent wear recovery due to aggressive stolons.
Growing Information
Origin Region
Native to coastal regions of the Americas, Caribbean, and Africa; adapted to humid subtropical and tropical climates
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners/stolons); forms a dense, coarse mat
Sunlight & Water Needs
Full sun to partial shade; possesses the best shade tolerance of warm-season grasses. High water requirement; poor drought tolerance compared to Bermuda.
Mowing & Maintenance
Recommended height of 2.5 to 4.0 inches. Fertilization: 2-4 lbs N/1000 sq ft annually. Requires moderate maintenance and regular dethatching to prevent spongy buildup.
Special Characteristics
High salt tolerance (excellent for coastal lawns); good shade tolerance; poor traffic tolerance compared to Bermuda; highly susceptible to Large Patch (Large Patch) and Chinch Bugs.
Ecological Information
Introduced/Naturalized in many regions; excellent soil stabilizer for coastal dune areas; can be invasive in non-native wetlands; often blended with other warm-season grasses in low-maintenance landscapes.