St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-type (likely a generic southern cultivar based on blade width and stolon size)
Hardiness Zones
USDA Hardiness Zones 8-11. Sensitive to frost; enters dormancy when soil temperatures drop below 55°F. Poor cold tolerance compared to Bermuda or Zoysia.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy sod. It maintains a deep green color in warm weather but turns brown and dormant during cold winters. In its unmowed state, it produces short, terminal flower spikes.
Blade Characteristics
Coarse width (8-10mm); flat shape with a distinct folded vernation in the bud. The tips are notably rounded or 'boat-shaped.' Color is a medium to dark green. It features a short, fringe-of-hairs ligule and lacks auricles.
Root System
Fibrous and relatively shallow to moderately deep; relies heavily on surface stolons for lateral expansion. Low thatch tendency if managed, but can build up if over-fertilized. Fast establishment from sod or plugs.
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 aggressively via thick, above-ground runners (stolons) to form a dense, coarse mat.
Sunlight & Water Needs
Partial sun to full sun (requires at least 4-5 hours of direct light); notably high shade tolerance for a warm-season grass. Requires moderate to high watering; poor performance in extreme drought without irrigation.
Mowing & Maintenance
Ideal height is 2.5 to 4.0 inches. Requires frequent mowing during peak summer. Fertilization: 2-4 lbs N per 1000 sq ft per year. Low to medium maintenance level overall.
Special Characteristics
Excellent shade tolerance among warm-season grasses; high salt tolerance (ideal for coastal regions); fair wear tolerance; susceptible to Chinch bugs and Gray Leaf Spot.
Ecological Information
Introduced/Naturalized in many regions. Provides excellent soil stabilization due to dense stolon mat. Low wildlife food value but provides cover for small invertebrates. Can be invasive in sensitive riparian ecosystems.