St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Palmetto' St. Augustine (exhibits good shade tolerance and semi-dwarf growth habit)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Susceptible to cold damage below freezing temperatures and goes into winter dormancy (turning brown) in the northern limits of its range.
About This Grass
A coarse-textured, dense, low-growing turfgrass with bright to dark green blades. Unmowed height reaches 6 to 12 inches, but when maintained it is typically kept between 2.5 and 4 inches. Produces flat, spike-like seed heads on terminal stalks during summer months.
Blade Characteristics
Blades are coarse in width (4-10 mm), flat, with blunt, rounded tips. Vernation is folded in the bud. Color ranges from light to medium-dark green. The ligule is a fringe of hairs, auricles are absent, and the collar region is continuous and often broad.
Root System
Shallow to moderate root depth consisting of fibrous roots originating from stolon nodes. Tends to build up thatch moderately fast. Fast establishment from sod, forming a thick, spongy sod layer that offers moderate wear recovery through stolon extension.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; widely cultivated in the Southern United States and tropical/subtropical regions worldwide.
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a dense, coarse-textured turf mat.
Sunlight & Water Needs
Performs best in full sun but has superior shade tolerance compared to most other warm-season grasses (requires at least 4 hours of direct sunlight). High water requirement; moderate drought tolerance entering dormancy during severe dry spells. Prefers well-drained soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower to prevent tearing the coarse blades. Requires medium-high maintenance, including 2 to 4 lbs N per 1000 sq ft annually, regular irrigation, and occasional dethatching due to rapid stolon production.
Special Characteristics
Excellent salt tolerance (making it popular for coastal properties), good shade tolerance relative to warm-season grasses, moderate traffic tolerance (slower to recover than Bermuda), and susceptible to chinch bugs and large patch disease.
Ecological Information
Introduced/cultivated in many tropical and subtropical areas. Provides good soil stabilization and erosion control on coastal sandy soils. Low invasive tendency outside cultivated landscapes, though stolons can invade adjacent flower beds.