St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-type (likely a standard residential cultivar)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing turfgrass with a prostrate growth habit. It is characterized by thick, succulent stolons and a distinct lime to medium-green color. When mowed, it creates a plush, carpet-like surface; unmowed, it can reach 6-12 inches. Seed heads are inconspicuous spikes with seeds embedded on one side of a flattened rachis.
Blade Characteristics
Wide (8-10mm), flat, with a distinct rounded or blunt "boat-shaped" tip. Vernation is folded in the bud. Ligule is a short fringe of hairs; auricles are absent. The collar is constricted and often lighter in color.
Root System
Moderately deep fibrous root system originating from stolon nodes; high thatch-forming tendency; slow to moderate establishment speed from sod or plugs; good wear recovery but poor traffic tolerance due to crushed stolons.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and West Africa; thrives in tropical and subtropical climates
Growth Habit
Stoloniferous (spreads aggressively via thick, above-ground runners), forming a dense, coarse mat
Sunlight & Water Needs
Partial sun to full sun (requires at least 4-5 hours); excellent shade tolerance for a warm-season grass; high water needs; moderate drought tolerance but wilts quickly without moisture; prefers pH 6.0-7.5.
Mowing & Maintenance
Mowing height 2.5-4.0 inches; frequency every 7-10 days; fertilization 2-4 lbs N per 1000 sq ft annually; requires frequent dethatching; overall high maintenance level.
Special Characteristics
High salt tolerance (ideal for coastal areas); excellent shade tolerance compared to Bermuda; susceptible to Chinch bugs and Large Patch (Grey Leaf Spot) disease; poor foot traffic tolerance.
Ecological Information
Introduced/Naturalized in many regions; provides soil stabilization in sandy coastal soils; generally non-invasive in non-irrigated wildlands but can dominate local garden ecosystems; often grown as a monoculture.