St. Augustine Grass
Stenotaphrum secundatum · Warm-season perennial, C4 carbon fixation pathway
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on common residential use and visible stolon thickness
Hardiness Zones
USDA Zones 8-11. Poor cold tolerance; enters dormancy and turns brown when temperatures drop below 55°F consistently.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy turf. Color ranges from deep blue-green to emerald green. Mowed height is typically 3-4 inches; seed heads are inconspicuous spikes with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse width (8-10mm), flat shape with a distinctively rounded or 'boat-shaped' tip. Vernation is folded in the bud; color is typically dark green. Ligule is a short fringe of hairs; auricles are absent; collar is continuous and narrowed.
Root System
Moderately deep fibrous roots with primary spread through thick surface stolons. High thatch-forming tendency; establishment speed is moderate via sod or plugs.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; well-adapted to humid subtropical climates.
Growth Habit
Stoloniferous; spreads via vigorous above-ground runners (stolons) that root at nodes to form a dense, carpet-like sod.
Sunlight & Water Needs
Prefers Full Sun but has the best shade tolerance among warm-season grasses (needs 4-6 hours). High water requirement; moderate drought tolerance but wilts quickly without moisture.
Mowing & Maintenance
Ideal height 3.5 to 4.0 inches. Weekly mowing; 2-4 lbs Nitrogen per 1000 sq ft annually. Requires periodic vertical mowing to manage heavy thatch. Maintenance level: Medium-High.
Special Characteristics
Excellent salt tolerance for coastal areas; poor wear tolerance (does not handle heavy foot traffic well); prone to Chinch bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in the US South. Provides soil stabilization in sandy coastal soils. Low wildlife value for forage but provides cover for small invertebrates. Often prone to invasiveness in non-managed tropical garden borders.