St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass; highly common in residential coastal landscapes
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on blade width and color
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; goes dormant and turns tan when temperatures drop below 55°F; susceptible to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It forms a dense, spongy turf that crowds out weeds. It typically remains 2-4 inches when mowed and produces short, thick flowering spikes under stress or when unmowed.
Blade Characteristics
Coarse blades (8-10mm wide), flat with rounded or 'boat-shaped' tips. Vernation is folded in the bud; ligule is a short fringe of hairs; auricles are absent. The collar is narrow and continuous.
Root System
Fibrous and relatively shallow compared to Centipede but supported by deep-reaching stolons. High thatch-forming tendency; moderate establishment speed from sod or plugs; poor wear recovery due to lack of rhizomes.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; well-adapted to the Southern United States and subtropical climates
Growth Habit
Stoloniferous; spreads via aggressive above-ground runners (stolons) that form a thick, carpet-like mat
Sunlight & Water Needs
Partial Sun to Full Sun (4-6 hours minimum); best shade tolerance among warm-season grasses. High water needs; poor drought tolerance; prefers well-drained, slightly acidic to neutral soils (pH 6.0-7.5).
Mowing & Maintenance
Mowing height: 2.5 to 4.0 inches. Frequency: Weekly during summer. Fertilization: 2-4 lbs Nitrogen per 1000 sq ft annually. Requires periodic vertical mowing to manage thatch. Maintenance level: Medium-High.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal yards); highly susceptible to Chinch bugs and Gray Leaf Spot disease; low traffic tolerance.
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in sandy coastal areas; low wildlife value in mowed turf; non-invasive in wild forest ecosystems but aggressive in landscaped garden beds.