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 or Floratam-like variety (highly coarse with blunt tips)
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; susceptible to winter kill in temperatures below 20°F. Enters dormancy when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy carpet. It has a medium-to-dark green color and maintains its hue well in warm weather, but turns brown/tan during winter dormancy. If unmowed, it can reach 6-12 inches, with seed heads appearing as short, thick spikes.
Blade Characteristics
Coarse blade width (8-10mm), flat shape with a distinctively blunt/rounded (boat-shaped) tip. Vernation is folded in the bud. Color is typically deep green. Ligules are short and fringed with hairs, and auricles are absent.
Root System
Deep fibrous root system paired with aggressive stolons. High thatch-forming tendency; establishes moderately fast via sod or plugs but not seed. Excellent recovery but slow to fill large bare spots compared to Bermuda.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, the Caribbean, and West Africa; adapted to tropical and subtropical climates
Growth Habit
Stoloniferous (spreads by thick above-ground runners), forms a dense, aggressive mat-like sod
Sunlight & Water Needs
Full Sun to Moderate Shade (one of the most shade-tolerant warm-season grasses); needs 4-6 hours of sun. Moderate to high water needs; low drought tolerance compared to other warm-season grasses.
Mowing & Maintenance
Mowing height 2.5 to 4.0 inches. Requires frequent mowing during peak summer. Fertilization: 2-4 lbs N 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 (good for coastal areas). Susceptible to Chinch bugs and Large Patch (brown patch) disease. Poor wear tolerance under heavy traffic.
Ecological Information
Introduced/Naturalized in many regions. Provides soil stabilization in sandy coastal areas. Low wildlife value in manicured lawns but can provide cover in naturalized settings. Can be invasive in unintended garden beds via stolons.