St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely Floratam or Palmetto based on leaf width and growth spacing)
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium to dark green color. It forms a thick carpet that crowds out most weeds. Seed heads are inconspicuous, appearing as spikes on a thickened, flattened stem (rachis) with small embedded spikelets.
Blade Characteristics
Coarse width (8-10mm), flat shape with a distinctively rounded or 'boat-shaped' tip. Vernation is folded in the bud. Color is typically a rich medium green. Ligule is a short fringe of hairs; auricles are absent; collar is constricted and narrow.
Root System
Relatively shallow but dense fibrous root system extending from nodes along stolons. High thatch-forming tendency. Moderately fast establishment from sod or plugs but not from seed.
Growing Information
Origin Region
Native to the coastal areas of the Gulf of Mexico, Caribbean, and Western Africa; well-adapted to tropical and subtropical climates
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners), forming a dense, coarse mat
Sunlight & Water Needs
Partial Sun to Full Sun (typically 4-6 hours minimum). Excellent shade tolerance compared to other warm-season grasses. High water needs; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
High maintenance. Recommended mowing height is 2.5 to 4.0 inches. Fertilization: 2-4 lbs N per 1000 sq ft per year. Frequent irrigation and periodic dethatching required.
Special Characteristics
Excellent shade tolerance, high salt tolerance (good for coastal areas), poor wear tolerance (does not recover quickly from heavy foot traffic), susceptible to Large Patch (fungus) and Chinch Bugs.
Ecological Information
Introduced/Naturalized in many regions. Provides soil stabilization in coastal sandy soils. Low wildlife food value but provides cover for small invertebrates. May become invasive in sensitive wetland margins.