St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4, not for cold transition zones
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass, Erosion Control
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on commonality and blade appearance
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance; will turn brown and enter dormancy when temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It remains lush in summer but goes dormant (tan/brown) in cold winters. Seed heads are spike-like with small seeds embedded in the rachis.
Blade Characteristics
Coarse (8-10mm width), flat blades with a distinct keeled shape and blunt, rounded tips. Vernation is folded in the bud; ligule is a short fringe of hairs; auricles are absent.
Root System
Relatively shallow to moderate fibrous root system arising from stolons; creates significant thatch; slow-to-moderate establishment from sod or plugs.
Growing Information
Origin Region
Native to coastal regions of the Caribbean, Africa, and the Mediterranean; performs best in humid, subtropical environments
Growth Habit
Stoloniferous (spreads aggressively via thick above-ground runners), forms a dense, carpet-like mat
Sunlight & Water Needs
Partial sun to full sun (4-6 hours minimum); high water requirements; moderate drought tolerance but prefers consistent moisture; pH 5.0-8.5.
Mowing & Maintenance
High maintenance; mowed at 3.0-4.0 inches; needs frequent nitrogen fertilization (1lb per 1000 sq ft during growing months); prone to thatch buildup.
Special Characteristics
Excellent shade tolerance compared to other warm-season grasses; high salt tolerance (ideal for coastal areas); poor wear/traffic tolerance due to thick stolons.
Ecological Information
Introduced and naturalized in southern US; provides good soil stabilization; can be invasive in sensitive wetlands; often used solo as it crowds out most other species.