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 (wild-type) or 'Floratam'
Hardiness Zones
USDA Zones 8-11. Poor cold tolerance; enters dormancy and turns brown when temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing turfgrass with thick, fleshy stolons. It features a medium to dark green color and forms a thick carpet that crowds out weeds. Seed heads are inconspicuous spikes with seeds embedded on one side of a flattened rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat, with a distinctly rounded or 'boat-shaped' tip. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent. Leaves are oppositely arranged on thick stolons.
Root System
Fibrous root system arising from stolon nodes; depth is moderate (up to 12 inches); low thatch tendency if managed; establishment speed is moderate via sod or plugs.
Growing Information
Origin Region
Coastal regions of the Americas, Caribbean, and Africa; thrives in tropical and subtropical climates
Growth Habit
Stoloniferous (spreads via thick above-ground runners), forming a dense, coarse mat
Sunlight & Water Needs
Prefers full sun but has excellent shade tolerance (one of the best for warm-season grasses). Requires regular watering; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches. Frequency is weekly during peak growth. Fertilization: 2-4 lbs N per 1000 sq ft annually. Maintenance level is moderate.
Special Characteristics
High shade tolerance for a warm-season grass, high salt tolerance (excellent for coastal areas), low wear tolerance (does not handle heavy foot traffic well).
Ecological Information
Introduced/Naturalized in the US. Provides soil stabilization in sandy coastal areas. Not considered highly invasive in managed landscapes but can spread into adjacent garden beds.