St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely Florida native or naturalized variety based on coarse texture and stolon internode length)
Hardiness Zones
USDA Hardiness Zones 8-10. Poor cold tolerance; enters dormancy and turns brown when temperatures drop below 50°F; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It is highly valued for its ability to form a thick carpet that competes well against weeds. When unmowed, it can reach 6-12 inches, but it is typically maintained as a dense turf. Seed heads are inconspicuous, appearing as a flattened spike with small seeds embedded in the rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat and smooth with a distinct rounded or blunt tip. Color is typically bright to medium green. Vernation is folded in the bud; ligule is a short fringe of hairs; auricles are absent. The collar region is continuous and narrow.
Root System
Fibrous roots originating from nodes along the thick stolons. It forms a moderate to deep root system but is prone to heavy thatch buildup. Establishment speed is moderate but effective via sod or plugs.
Growing Information
Origin Region
Native to the coastal areas of the Gulf of Mexico, Caribbean, and Western Africa; well-adapted to the Southern United States and tropical climates.
Growth Habit
Stoloniferous (spreads via vigorous above-ground runners), forming a dense, coarse-textured mat.
Sunlight & Water Needs
Partial Sun to Full Sun; noted as one of the most shade-tolerant warm-season grasses (requires 4-5 hours of sun). High water needs; poor drought tolerance compared to Bermuda, preferring moist, well-drained soils with a pH of 5.0 to 8.5.
Mowing & Maintenance
Recommended mowing height is 2.5 to 4.0 inches. Mowing frequency is weekly during peak growth. Requires 2-4 lbs of Nitrogen per 1000 sq ft per year. High maintenance level due to water needs and susceptibility to pests/thatch.
Special Characteristics
Excellent shade tolerance for a warm-season grass, high salt tolerance (ideal for coastal areas), and moderate traffic tolerance. Highly susceptible to Chinch Bugs and Large Patch (Rhizoctonia).
Ecological Information
Introduced/Naturalized in many regions. Provides soil stabilization in coastal sandy areas. Not considered invasive in managed landscapes but can crowd out native species in damp, coastal riparian zones if left unmanaged.