St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Panicoideae, Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam, characterized by wider blades and purplish stolons
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy when temperatures drop below 55°F; prone to winter kill in transition zones.
About This Grass
A coarse-textured, low-growing turfgrass that forms a dense, carpet-like sod. It displays a deep blue-green to medium-green color during the growing season and goes dormant (tan/brown) in cold winters. Seed heads are inconspicuous spikes.
Blade Characteristics
Coarse width (8-10mm); flat shape with a blunt, rounded 'boat-shaped' or folded tip; dark green color; folded vernation; short, fringe-like hairy ligule; auricles are absent; collar is constricted and smooth.
Root System
Fibrous and relatively shallow compared to Bermuda grass; relies on stolons for lateral spread; moderate thatch-forming tendency; slow to moderate establishment from plugs or sod.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; well-adapted to USDA zones 8-11
Growth Habit
Stoloniferous; spreads aggressively above ground via thick, creeping runners (stolons) to form a dense, spongy mat
Sunlight & Water Needs
Partial sun to Full sun (needs at least 4-5 hours); high shade tolerance compared to other warm-season grasses; high water needs; moderate drought tolerance but prefers consistent moisture; pH 5.0-8.5.
Mowing & Maintenance
Ideal height of 2.5 to 4.0 inches; weekly frequency; fertilization of 2-4 lbs N/1000 sq ft per year; high maintenance due to water and pest (Chinch bug) needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear/traffic tolerance due to fleshy stolons; thick sod crowds out most weeds.
Ecological Information
Introduced/Naturalized in US; provides soil stabilization in coastal sandy areas; low wildlife value in mowed turf form; can be invasive in some sensitive humid environments; often grown as a mono-stand.