St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' (based on blade width and color)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F; prone to winter kill in transition zones.
About This Grass
A coarse-textured, low-growing grass with a deep blue-green color. It forms a dense, spongy turf that is highly competitive against weeds. In its unmowed state, it can reach 6-12 inches, with seed heads appearing as small, thickened spikes along the stem.
Blade Characteristics
Broad blades (8-10mm), linear shape with a rounded or 'boat-shaped' tip; folded vernation in the bud; collar is constricted; ligule is a short fringe of hairs; auricles are absent.
Root System
Relatively shallow fibrous root system supported by thick, fleshy stolons; forms heavy thatch; moderate establishment speed from sod or plugs; poor drought recovery compared to Bermuda.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Africa; well-adapted to tropical and subtropical climates
Growth Habit
Stoloniferous (spreads via vigorous above-ground runners); creates a thick, carpet-like mat
Sunlight & Water Needs
Prefers full sun but has excellent shade tolerance for a warm-season grass (needs 4-6 hours); high water requirement; prefers well-drained, slightly acidic to neutral soil (pH 6.0-7.5).
Mowing & Maintenance
Ideal height: 2.5-4.0 inches; frequency: every 7-10 days during peak growth; fertilization: 2-4 lbs N/1000 sq ft/year; medium-high maintenance due to irrigation and pest monitoring.
Special Characteristics
Exceptional shade tolerance (the best among warm-season grasses); high salt tolerance (good for coastal areas); moderate wear tolerance but slow to recover; susceptible to Chinch bugs and Large Patch disease.
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in sandy coastal areas; low wildlife value beyond cover for small insects; can be invasive in native wetland margins; often grown as a monostand.