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 (identifiable by coarse texture and broad blades)
Hardiness Zones
USDA Hardiness Zones 8-11; low cold tolerance; goes dormant below 55°F; prone to winter kill in temperatures below 20°F.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy mat. It is characterized by its light to medium green color and wide, blunt-tipped blades. It stays green year-round in frost-free zones but goes dormant and turns brown after a hard freeze.
Blade Characteristics
Coarse blade width (8-10mm); folded vernation; blades are flat with a distinct 'boat-shaped' or rounded, blunt tip; light to dark green color; ligule is a short fringe of hairs; auricles are absent.
Root System
Fibrous and relatively shallow, though stolons provide significant surface coverage. It has a high thatch-forming tendency and moderate establishment speed from sod or plugs.
Growing Information
Origin Region
Native to the Gulf of Mexico region, West Indies, and Western Africa; best in tropical and subtropical coastal climates.
Growth Habit
Stoloniferous; spreads via thick, creeping above-ground runners (stolons) to form a dense, carpet-like sod.
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses); needs at least 4-5 hours of direct sun; high water requirement; moderate drought tolerance but wilts quickly without moisture; prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Mowing height 2.5 to 4.0 inches; weekly frequency during growing season; 2-4 lbs Nitrogen per 1000 sq ft annually; medium maintenance level; sensitive to certain herbicides.
Special Characteristics
High shade tolerance for a warm-season grass; excellent salt tolerance (ideal for coastal areas); poor wear tolerance due to succulent stolons; susceptible to Chinch Bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in the US south; provides soil stabilization in sandy coastal areas; low wildlife value; not considered invasive in managed landscapes but can crowd out weaker grasses.
Notes
Backyard