St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4, non-transition zone
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass, Erosion Control
Variety / Cultivar
Common or Floratam-type (based on coarse stolon thickness and wide blades visible in living sections)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; leaves turn brown and dormant when temperatures consistently drop below 55°F.
About This Grass
A coarse-textured, low-growing turfgrass that forms a dense, carpet-like mat. In and out of dormancy, it transitions from a vibrant deep green to a tan/brown straw color. It produces compressed, flowering spikes (spicate racemes) on short stalks.
Blade Characteristics
Coarse (8-10mm wide), flat, with a distinct rounded or blunt tip. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent. Leaves are arranged alternately along thick, fleshy stolons.
Root System
Deep fibrous root system when healthy; establishes primarily through stolons that root at every node. High thatch-forming tendency due to thick stolon accumulation.
Growing Information
Origin Region
Native to coastal regions of Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical and subtropical climates
Growth Habit
Stoloniferous (spreads aggressively via thick above-ground runners)
Sunlight & Water Needs
Full Sun to Moderate Shade (most shade-tolerant warm-season grass); high water requirement during growth; moderate drought tolerance but enters dormancy quickly under stress.
Mowing & Maintenance
Ideal height 3.5 to 4.0 inches; weekly frequency; requires 2-4 lbs N per 1000 sq ft annually; high maintenance due to dethatching requirements and susceptibility to Chinch bugs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear/traffic tolerance due to thick, brittle stolons.
Ecological Information
Introduced/Naturalized in US; provides soil stabilization for sandy coastal soils; susceptible to Large Patch (fungus) and Chinch bugs; often used as monostand as it does not blend well with fine-textured grasses.