St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely wild-type or 'Floratam' based on leaf width and internode color)
Hardiness Zones
USDA Hardiness Zones 8–11; poor cold tolerance; enters dormancy and turns brown when temperatures drop below 55°F; prone to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy carpet. Light to medium green in color, it remains green into late autumn in warm climates. Seed heads are inconspicuous spikes with seeds embedded on one side of a flattened rachis.
Blade Characteristics
Blade width >4mm (coarse); folded in the bud (folded vernation); tip is rounded/boat-shaped; blades are flat and wide with a constricted collar; no auricles; ligule is a short fringe of hairs.
Root System
Fibrous and moderately deep, emerging from nodes along the stolons; produces heavy thatch; slow to establish from seed, usually established via sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico, Caribbean, and Western Africa; thrives in tropical and subtropical coastal climates
Growth Habit
Stolons only (no rhizomes); spreads via thick above-ground runners to form a dense, coarse mat
Sunlight & Water Needs
Partial sun to full sun; one of the most shade-tolerant warm-season grasses (needs 4-6 hours); high water requirement; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
Mowing height 2.5–4.0 inches; weekly frequency; fertilization 2-4 lbs Nitrogen/1000 sq ft annually; medium maintenance level; needs occasional dethatching.
Special Characteristics
Excellent salt tolerance (ideal for coastal lawns); moderate wear tolerance (due to stolons); highly susceptible to Chinch Bugs and Large Patch (brown patch) disease.
Ecological Information
Native to coastal regions; provides good soil stabilization for erosion control; non-invasive in most landscapes compared to Bermuda grass; often mixed with other warm-season cultivars in sod production.