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 / Floratam type
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; enters dormancy and turns brown when temperatures drop below 55°F (13°C) or during frost.
About This Grass
A coarse-textured, low-growing grass with a deep green color. It forms a thick sod through vigorous stolon growth. When unmowed, it produces spike-like seed heads; when maintained, it provides a lush, carpet-like appearance but is prone to thatch buildup.
Blade Characteristics
Coarse blades (8-10mm wide), flat to slightly folded. Tips are distinctly rounded or boat-shaped. Color is medium to dark green. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent. The collar is narrow and continuous.
Root System
Fibrous and relatively shallow to moderate depth; relies heavily on thick, fleshy stolons for lateral expansion. High thatch-forming tendency; moderate establishment speed from sod or plugs.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, the Caribbean, and West Africa; well-adapted to tropical and subtropical climates.
Growth Habit
Stoloniferous (spreads via above-ground runners), forming a dense, coarse-textured mat with a moderate to fast spread rate.
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses). Requires at least 4-5 hours of direct sun. High water needs; poor drought tolerance compared to Bermuda, prefers well-drained loamy or sandy soils with pH 5.0-8.5.
Mowing & Maintenance
Mowing height of 2.5 to 4.0 inches. Weekly frequency during peak growth. Fertilization: 2-4 lbs N per 1000 sq ft annually. High maintenance level due to water needs and susceptibility to pests.
Special Characteristics
Excellent shade tolerance for a warm-season grass. High salt tolerance (suitable for coastal areas). Poor wear tolerance (sensitive to heavy foot traffic). Susceptible to Chinch bugs and Gray Leaf Spot disease.
Ecological Information
Introduced/Naturalized in many regions. Provides soil stabilization in coastal ecosystems. Historically used for pasture but primarily a turf grass today. Not considered highly invasive in managed landscapes but can crowd out native flora in moist, shaded coastal margins.