St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4 photosynthetic pathway
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; turns brown and enters dormancy following the first frost.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It forms a thick sod that crowds out most weeds. Seed heads are spike-like racemes with seeds embedded in a flattened, fleshy stalk.
Blade Characteristics
Coarse blades (>4mm wide), folded in the bud (vernation). Blades are flat with a rounded or slightly blunt apex. Ligule is a short fringe of hairs; auricles are absent. The collar is continuous and somewhat constricted.
Root System
Principally stoloniferous with a moderately deep fibrous root system. High thatch-forming tendency due to the density of stolons. Slower to establish from seed compared to stolons/plugs.
Growing Information
Origin Region
Native to the tropical and subtropical regions of the Americas and Africa; common in coastal Gulf Coast, Florida, and California.
Growth Habit
Stoloniferous; spreads aggressively via thick, creeping above-ground runners (stolons) to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial sun to full sun (4-6 hours minimum); best shade tolerance among warm-season grasses. High water requirement, especially during summer; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
High maintenance. Recommended mowing height of 2.5 to 4.0 inches. Fertilization requires 2-4 lbs of Nitrogen per 1000 sq ft annually. Requires periodic dethatching and aeration.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance for coastal regions; poor wear tolerance (recovery is slow if stolons are crushed). Susceptible to Chinch bugs and Large Patch disease.
Ecological Information
Naturalized in many coastal zones; provides excellent soil stabilization and erosion control. Can be invasive in sensitive wetland ecosystems but is generally a preferred non-invasive choice for residential lawns.