St. Augustine Grass
Stenotaphrum secundatum · Warm-season (C4), Perennial, suited for tropical and subtropical climates
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto', noted for wide, coarse blades and vigorous stolon growth
Hardiness Zones
USDA Hardiness Zones 8-11. Excellent heat tolerance but poor cold tolerance; will go dormant (turn brown) when temperatures drop below 55°F and can be killed by hard freezes.
About This Grass
A coarse-textured, low-growing grass that forms a thick, carpet-like sod. It is deep green to blue-green in color, maintaining its hue well into autumn. Unmowed, it can reach 6-12 inches, but it is typically maintained as a lush turf. Seed heads are spike-like racemes with seeds embedded in a flattened rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat, with a distinctively rounded or 'boat-shaped' tip. Color varies from bright green to dark blue-green. Vernation is folded in the bud. The ligule is a short fringe of hairs, auricles are absent, and the collar is continuous and narrow.
Root System
Mainly stoloniferous with a fibrous root system that can reach moderate depths. It has a high thatch-forming tendency and establishes relatively quickly from sod or plugs but not from seed.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, the Caribbean, and West Africa; adapted to Mediterranean and subtropical climates
Growth Habit
Stoloniferous (spreads via above-ground runners), forming a dense, coarse-textured mat with a moderate to fast rate of spread
Sunlight & Water Needs
Partial sun to full sun (prefers 4-6 hours minimum); among the most shade-tolerant of warm-season grasses. High water needs; poor drought tolerance compared to Bermuda, preferring moist, well-drained soils with a pH of 5.0 to 8.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4.0 inches. Requires frequent mowing during peak summer. Fertilization needs are medium to high (2-4 lbs N per 1000 sq ft per year). Requires periodic dethatching and aeration. Moderate to high maintenance level.
Special Characteristics
Excellent shade tolerance for a warm-season grass, high salt tolerance (ideal for coastal areas), and good wear tolerance, though it recovers slowly from heavy damage due to lack of rhizomes.
Ecological Information
Introduced and naturalized in many warm coastal areas. Provides soil stabilization in sandy coastal soils. It is not considered highly invasive in managed landscapes but can crowd out native species in sensitive wetland margins. Often used as a mono-stand rather than in blends.