St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-type (likely standard residential variety)
Hardiness Zones
USDA Zones 8-11. Poor cold tolerance; turns dormant at temperatures below 55°F and can suffer winter kill in Zone 8a/7b.
About This Grass
A coarse-textured, low-growing grass that forms a thick sod. It maintains a deep blue-green color in optimal conditions but goes dormant (brown) in cold weather. It features thick, fleshy stolons and broad, blunt-tipped blades.
Blade Characteristics
Coarse width (>4mm), flat shape with a distinct boat-shaped to rounded tip. Color is mid-to-dark green. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent; the collar is constricted and distinct.
Root System
Fibrous and dense, primarily extending from nodes along the stolons. Establishment is moderate to slow (primarily via sod or plugs). It forms significant thatch due to the heavy stolon structure.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, Caribbean, and Western Africa; highly adapted to Tropical and Subtropical climates
Growth Habit
Stoloniferous (spreads via thick, creeping above-ground runners), forming a dense, coarse mat
Sunlight & Water Needs
Partial Sun to Full Sun; best shade tolerance among warm-season grasses (needs 4-6 hours). High water requirement; moderate drought tolerance but wilts quickly without irrigation.
Mowing & Maintenance
High maintenance. Ideal height: 2.5 to 4.0 inches. Requires frequent mowing to prevent thatch buildup. Fertilization: 3-6 lbs Nitrogen per 1000 sq ft per year. High dethatching and aeration needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass, high salt tolerance (ideal for coastal areas), poor wear tolerance compared to Bermuda, but excellent at crowding out weeds once established.
Ecological Information
Native to coastal regions. Provides low-level cover for small insects. Effective for soil stabilization in sandy coastal soils. Low invasive potential in non-tropical inland environments but can be aggressive in citrus groves or wetlands.