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 blade width and dark green color)
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance, enters dormancy and turns brown when temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass that forms a thick, carpet-like sod. It is deep green to blue-green in color and retains color well into autumn. Unmowed, it can reach 6-12 inches; maintained, it creates a dense cover. Seed heads are inconspicuous spikes with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse blades (>4mm wide), flat to folded, with a distinctively rounded or 'boat-shaped' tip. Color is typically medium to dark green. Vernation is folded in the bud. It lacks auricles and has a short, fringe-of-hairs ligule. The collar is continuous and somewhat constricted.
Root System
Fibrous and moderately deep, primarily extending from nodes along the stolons. It has a high thatch-forming tendency and slow-to-moderate establishment speed from sod or plugs (rarely grown from seed).
Growing Information
Origin Region
Native to Gulf Coast region, Caribbean, and Africa; well-adapted to tropical and subtropical coastal regions.
Growth Habit
Stoloniferous (spreads via aggressive above-ground runners/stolons); forms a dense, thick mat.
Sunlight & Water Needs
Preferred Full Sun but has excellent shade tolerance (one of the best for warm-season grasses). Requires moderate to high watering; low drought tolerance compared to Bermuda grass. Prefers moist, well-drained soils with pH 5.0-8.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4.0 inches. Frequency: weekly during peak growth. Fertilization: 2-4 lbs Nitrogen per 1000 sq ft/year. Requires periodic dethatching and aeration. High maintenance level.
Special Characteristics
Excellent shade tolerance and salt tolerance (ideal for coastal lawns). High wear tolerance but slow recovery rate. Susceptible to Chinch bugs and Gray Leaf Spot disease.
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in coastal sandy areas; low food value for wildlife but provides dense cover; can be invasive in non-managed tropical garden borders.