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 typical residential use)
Hardiness Zones
USDA Hardiness Zones 8-11. Excellent heat tolerance; poor cold tolerance (turns brown/dormant quickly after the first frost; can be killed by hard freezes).
About This Grass
A coarse-textured, low-growing grass with a deep blue-green to emerald green color. It forms a thick sod that crowds out most weeds. Seed heads remain low and appear as spikes with embedded spikelets on one side of a flattened rachis.
Blade Characteristics
Coarse width (>4mm), folded in the bud (folded vernation), rounded or blunt tips, smooth texture with a prominent midrib. The ligule is a short fringe of hairs, and auricles are absent. The collar is constricted and smooth.
Root System
Moderately deep fibrous root system originating from nodes along thick stolons. It has a high thatch-forming tendency due to the density of the stolons and provides moderate drought tolerance once established.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, the Caribbean, and parts of West Africa; well-adapted to subtropical and tropical climates.
Growth Habit
Stoloniferous (spreads aggressively via thick above-ground runners); forms a dense, carpet-like mat.
Sunlight & Water Needs
Partial sun to full sun; one of the most shade-tolerant warm-season grasses (needs 4-6 hours of light). Requires regular watering (1 inch per week) and prefers well-drained, slightly acidic to neutral soils.
Mowing & Maintenance
Ideal height is 2.5 to 4.0 inches. Maintain via frequent mowing to prevent thatch buildup. Requires 2-4 lbs of Nitrogen per 1000 sq ft per year. High maintenance level due to water and pest needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); poor wear/traffic tolerance compared to Bermuda; susceptible to Chinch bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in many regions. Provides excellent soil stabilization and erosion control due to dense stolon mat. Not considered a significant wildlife food source, but provides cover for small invertebrates.