St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass, Erosion Control
Variety / Cultivar
Common St. Augustine / Floratam (Likely native or common variety)
Hardiness Zones
USDA Zones 8–11. Poor cold tolerance; turns brown and goes dormant quickly after the first frost. High heat tolerance.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It is known for its thick, creeping stolons and ability to form an extremely dense sod that crowds out most weeds.
Blade Characteristics
Coarse width (4-10mm), flat shape with a distinct rounded or blunt 'boat-shaped' tip. Vernation is folded in the bud. Light to medium green color. Ligule is a fringe of short hairs; auricles are absent.
Root System
Moderately deep fibrous root system originating from nodes on thick stolons. High thatch-forming tendency; slow to moderate establishment from plugs/sod but creates a massive sod layer once established.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; thrives in tropical and subtropical climates.
Growth Habit
Stoloniferous (spreads aggressively via thick above-ground runners), forming a dense, coarse-textured mat.
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses). Requires high water availability; poor drought tolerance compared to Bermuda, prefers slightly acidic to neutral soil (pH 5.0-8.5).
Mowing & Maintenance
High maintenance. Recommended mowing height: 2.5–4.0 inches. Fertilization: 2-4 lbs N per 1000 sq ft per year. Frequent irrigation required in dry periods. Susceptible to thatch buildup requiring vertical mowing.
Special Characteristics
Excellent shade tolerance for a warm-season grass. High salt tolerance (ideal for coastal areas). Susceptible to Chinch bugs and Large Patch (Rhizoctonia). Poor wear tolerance due to succulent stolons.
Ecological Information
Introduced/Naturalized in the US. Provides fair soil stabilization. Can become invasive in garden beds due to stoloniferous spread. Often found in proximity to Bermuda grass (Cynodon dactylon) as seen in the image.