St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine / Floratam type; notable for wide, coarse blades and aggressive stoloniferous growth.
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy below 55°F; can be damaged by prolonged hard freezes.
About This Grass
A coarse-textured, low-growing turfgrass that forms a thick, spongy sod. It maintains a deep green to blue-green color in warm months and becomes straw-colored during winter dormancy. Unmowed, it can reach 6-12 inches; seed heads are inconspicuous spikes with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse width (>4mm); flat shape with a distinctively rounded/blunt tip; medium to dark green color; folded vernation; short fringe of hairs for a ligule; auricles are absent; collar is continuous and narrowed.
Root System
Moderately deep fibrous roots originating from stolon nodes; high thatch-forming tendency; slow to moderate establishment from plugs or sod; forms a very dense sod that recovers well if stolons are intact.
Growing Information
Origin Region
Coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical and subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively via thick above-ground runners (stolons) to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial Sun to Full Sun; best shade tolerance among warm-season grasses (requires 4-5 hours direct sun); high water needs; moderate drought tolerance but wilts quickly without moisture; prefers slightly acidic to neutral soil (pH 6.0-7.5).
Mowing & Maintenance
Ideal height 2.5 to 4.0 inches; mow every 7-10 days; 2-4 lbs N per 1000 sq ft per year; requires periodic vertical mowing to manage thatch; medium maintenance level.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear tolerance due to succulent stolons; susceptible to Chinch bugs and Gray Leaf Spot.
Ecological Information
Native to coastal areas of North and South America; provides soil stabilization in sandy coastal soils; generally not invasive in non-wetland inland areas; often grown as a mono-stand rather than in mixes.