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 variety: 'Floratam' or 'Palmetto' based on blade width and growth density)
Hardiness Zones
USDA Hardiness Zones 8-11. Excellent heat tolerance; poor cold tolerance; will go dormant and turn brown when temperatures drop below 55°F (13°C).
About This Grass
A coarse-textured, low-growing grass with a dense, carpet-like habit. It maintains a medium-to-dark green color and produces short, thick flowering spikes (racemes) with embedded seeds along one side of a flattened rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat, with a distinct rounded or 'boat-shaped' tip. Vernation is folded in the bud. Color is typically deep green. The ligule is a short fringe of hairs, and auricles are absent.
Root System
Fibrous and moderately deep; primarily established through stolons which root at the nodes. High thatch-forming tendency but provides excellent sod stability.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; well-adapted to tropical and subtropical climates.
Growth Habit
Stoloniferous; spreads via aggressive above-ground runners (stolons) that form a thick, sod-forming mat. It does not have underground rhizomes.
Sunlight & Water Needs
Partial Shade to Full Sun; one of the most shade-tolerant warm-season grasses. Requires moderate to high watering; low drought tolerance compared to Bermuda grass; prefers well-drained, slightly acidic to neutral soils (pH 6.0-7.5).
Mowing & Maintenance
Ideal mowing height: 2.5 to 4.0 inches. Frequency: weekly during growing season. Fertilization: 2-4 lbs Nitrogen per 1,000 sq ft per year. High maintenance level; prone to thatch buildup requiring occasional vertical mowing.
Special Characteristics
High shade tolerance (for a warm-season grass), high salt tolerance (excellent for coastal areas), and high wear recovery due to stolon growth, though it does not handle high-frequency traffic as well as Bermuda.
Ecological Information
Introduced/Naturalized in many southern US states. Provides soil stabilization and prevents erosion. Generally non-invasive in non-coastal ecosystems; often used as a mono-culture lawn but can be vulnerable to Chinch bugs and Large Patch (Rhizoctonia).