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' based on blade width and dark green color
Hardiness Zones
USDA Zones 8-11; poor cold tolerance, enters dormancy below 55°F, and can be killed by prolonged freezing temperatures.
About This Grass
A coarse-textured, low-growing turfgrass that forms a thick, spongy mat. It maintains a deep green color in warm weather but turns brown/dormant during winter frosts.
Blade Characteristics
Wide (6-10mm), flat blades with a distinct rounded or 'boat-shaped' tip; vernation is folded, ligule is a fringe of hairs, auricles are absent, and the leaf sheath is highly compressed.
Root System
Fibrous and relatively shallow, though deep for a turfgrass; high thatch tendency due to heavy stolon growth; establishment is primarily via sod or plugs as it produces few viable seeds.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical and subtropical climates
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners); forms a dense, carpet-like sod
Sunlight & Water Needs
Full sun to moderate shade (one of the most shade-tolerant warm-season grasses); high water requirements with moderate drought tolerance; prefers well-drained, slightly acidic to neutral soils.
Mowing & Maintenance
High maintenance; mowing height 3.0-4.0 inches; requires frequent fertilization (2-4 lbs N per 1000 sq ft annually) and regular dethatching.
Special Characteristics
Excellent salt tolerance (suitable for coastal areas), high shade tolerance compared to Bermuda, poor wear tolerance due to succulent stolons, prone to Chinch Bugs and Large Patch disease.
Ecological Information
Introduced in many areas but naturalized in coastal ecosystems; provides excellent soil stabilization and erosion control but can be invasive in sensitive wetland margins.