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 non-dwarf given blade width)
Hardiness Zones
USDA Zones 8–11; very poor cold tolerance; enters dormancy (turns brown) when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a dense, carpet-like habit. It exhibits a vibrant medium to dark green color, maintaining depth in high temperatures. Seed heads are inconspicuous spikes attached to a thick, flattened stem.
Blade Characteristics
Coarse blades >4mm wide; flat surface with a distinct rounded/obtuse tip; folded vernation; ligule is a fringe of short hairs; auricles are absent; collar is constricted and smooth.
Root System
Moderately deep fibrous roots originating from stolon nodes; forms a dense sod but has high thatch-forming tendencies; slow to moderate establishment speed.
Growing Information
Origin Region
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)
Sunlight & Water Needs
Partial sun to full sun (best shade tolerance among warm-season grasses); needs 4-6 hours direct light; high water requirement; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
Ideal height 2.5–4.0 inches; weekly frequency; requires 2-4 lbs N per 1,000 sq ft annually; high maintenance level due to pest/water needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear tolerance due to succulent stolons; susceptible to Chinch Bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in US; provides soil stabilization in sandy coastal areas; low wildlife value; not considered invasive in managed landscapes but can crowd out native flora in wetlands.