St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Floratam', known for its large leaves, purple-tinted stolons, and high resistance to St. Augustine Decline (SAD) virus.
Hardiness Zones
USDA Hardiness Zones 8-10. Excellent heat tolerance, poor cold tolerance (suffers freeze damage below 20°F). Goes dormant and turns brown during cool winters.
About This Grass
St. Augustine grass is a coarse-textured, warm-season turfgrass known for its lush, blue-green to dark green color and thick growth habit. Unmowed, it can grow up to 6-12 inches tall, but when maintained, it creates a dense, spongy carpet. It produces flat, thick stems and spikes as seed heads.
Blade Characteristics
Blades are coarse, typically 4-10 mm wide, flat with blunt or rounded tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar region is continuous and narrow.
Root System
Moderately deep fibrous root system originating from nodes along the thick surface stolons. Forms a heavy thatch layer over time. Establishes rapidly from sod but slower from plugs. Moderate drought tolerance, recovers well from wear via stolon growth.
Growing Information
Origin Region
Native to tropical and subtropical coastal regions of the Gulf of Mexico, the Caribbean, and the Mediterranean. Cultivated extensively in the southern United States and tropical regions worldwide.
Growth Habit
Stoloniferous (spreading aggressively above ground via thick runners or stolons), forming a coarse, dense turf mat.
Sunlight & Water Needs
Requires full sun to partial shade (more shade tolerant than most warm-season grasses, needing at least 4 hours of direct sunlight). High water requirement during active growth, moderate drought tolerance by entering dormancy. Prefers moist, fertile soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a rotary mower. Mow every 7-10 days during the growing season. Fertilize at 2-4 lbs N per 1000 sq ft annually. Regular dethatching and core aeration may be necessary due to thick thatch production. High maintenance level.
Special Characteristics
Moderate traffic tolerance, susceptible to chinch bugs, sod webworms, take-all root rot, and brown patch. Good salt tolerance, making it popular for coastal properties. Moderate shade tolerance compared to other warm-season grasses.
Ecological Information
Introduced and naturalized in many tropical and subtropical areas. Provides good ground cover and soil stabilization in coastal areas. Low wildlife food value compared to native grasses. Often grown as a standalone monoculture lawn.