St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto'
Hardiness Zones
USDA Zones 8-11; poor cold tolerance, turns dormant below 55°F; does not survive ground freezes well.
About This Grass
A coarse-textured, low-growing turfgrass that forms a thick sod. It maintains a deep green to blue-green color in warm months and goes dormant (tan) in winter. Seed heads are spike-like racemes but are often sterile in cultivars.
Blade Characteristics
Coarse width (>4mm), folded in the bud (vernation), with rounded or blunt tips. Blades are smooth on both sides with a short, fringed membranous ligule and no auricles.
Root System
Extensive fibrous roots with heavy reliance on thick, fleshy stolons for lateral spread. Forms heavy thatch; moderate establishment speed from sod or plugs; excellent wear recovery.
Growing Information
Origin Region
Native to Gulf of Mexico, Caribbean, and Mediterranean regions; adapted to humid subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively via above-ground runners to form a dense, carpet-like mat.
Sunlight & Water Needs
Requires Full Sun to Partial Shade; one of the most shade-tolerant warm-season grasses. Needs 1 inch of water per week; moderate drought tolerance but prefers moist, well-drained soils; pH 5.0-8.5.
Mowing & Maintenance
Height: 3.5 to 4.0 inches; frequency: weekly during peak growth. Fertilization: 2-4 lbs N/1000 sq ft/year. Requires periodic dethatching; High maintenance level.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); susceptible to Chinch bugs and Gray Leaf Spot; poor traffic tolerance compared to Bermuda.
Ecological Information
Introduced/Naturalized in US; provides soil stabilization in coastal ecosystems; can be invasive in non-managed tropical wetlands; often blended with other St. Augustine cultivars but rarely other species.