St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common (appears to be a non-dwarf, standard cultivar like 'Palmetto' or 'Floratam')
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance; enters dormancy when temperatures drop below 55°F consistently.
About This Grass
A coarse-textured, low-growing grass that forms a thick sod. It maintains a medium-to-dark green color throughout the growing season and turns brown during winter dormancy. The plant is characterized by its wide blades and thick, fleshy stolons. Seed heads are spike-like racemes but are often sterile or produce low-viability seeds.
Blade Characteristics
Coarse width (>4mm), flat shape with a distinct rounded or blunt tip; color is medium green; vernation is folded; ligule is a short fringe of hairs; auricles are absent; collar is constricted and distinct.
Root System
Relatively shallow fibrous root system emanating from stolon nodes; high thatch-forming tendency; establishment speed is moderate to fast via sod or plugs; poor wear recovery but good sod density.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Western Africa; well-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 (one of the most shade-tolerant warm-season grasses); needs at least 4-5 hours of sun; high water requirements; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
Ideal height: 2.5 to 4.0 inches; frequency: weekly during peak growth; fertilization: 2-4 lbs Nitrogen per 1000 sq ft annually; high maintenance due to water and pest needs; requires periodic vertical mowing to manage thatch.
Special Characteristics
Excellent shade tolerance compared to other warm-season grasses; high salt tolerance (excellent for coastal areas); susceptible to Large Patch (fungus) and Chinch Bugs; poor traffic tolerance.
Ecological Information
Introduced/Naturalized in the Southern USA; provides soil stabilization in sandy coastal areas; low wildlife value; not typically considered invasive in managed landscapes but can aggressively overtake weaker grasses via stolons.