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 (likely Florida native type or 'Floratam' based on blade width)
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance; enters dormancy when soil temperatures drop below 55°F; susceptible to winter kill in upper transition zones.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy sod. It maintains a deep green to blue-green color in warm months and goes dormant (tan/brown) after heavy frost. Seed heads are inconspicuous spikes with flowers embedded in a flattened rachis.
Blade Characteristics
Coarse blade width (8-10mm); flat shape with a distinctively rounded or 'boat-shaped' tip; leaves are folded in the bud (folded vernation); short, fringe-like hairy ligule; auricles are absent; collar is continuous and narrowed.
Root System
Moderately deep fibrous root system originating from stolon nodes; high thatch-forming tendency; slow to moderate establishment from plugs or sod; creates a very dense sod that competes well with weeds.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; adapted to tropical and subtropical climates
Growth Habit
Stoloniferous; spreads via thick above-ground runners (stolons) to form a dense, carpet-like mat
Sunlight & Water Needs
Partial Shade to Full Sun; one of the most shade-tolerant warm-season grasses (needs 4-5 hours minimum); high water requirements; moderate drought tolerance but wilts quickly without supplemental irrigation.
Mowing & Maintenance
Mowing height of 2.5 to 4.0 inches; weekly frequency; fertilization of 2-4 lbs Nitrogen per 1000 sq ft per year; high maintenance level due to water and pest needs; periodic dethatching required.
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; provides soil stabilization in sandy regions; high water filtration value due to density; can be invasive in non-native wetlands; often used as a monoculture but can coexist with Centipede grass in some regions.