St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-type (likely due to medium-coarse texture and presence of reddish-purple stolons)
Hardiness Zones
USDA Hardiness Zones 8-11; poor cold tolerance; enters dormancy and turns brown when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing turfgrass that forms a dense, carpet-like mat. It is bright to dark green and remains green longer into the fall than Bermuda grass. When unmowed, it produces short, spike-like seed heads on thin stalks.
Blade Characteristics
Coarse blade width (8-10mm), flat shape with a distinct rounded or 'boat-shaped' tip; vernation is folded in the bud; ligule is a fringe of short hairs; auricles are absent; collar is constricted.
Root System
Relatively shallow fibrous root system originating from stolon nodes; high thatch-forming tendency; moderate establishment speed from sod or plugs; poor wear recovery due to lack of rhizomes.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and West Africa; best in tropical and subtropical climates
Growth Habit
Stoloniferous (spreads aggressively via thick, above-ground runners)
Sunlight & Water Needs
Partial Sun to Full Sun; thrives on 4-6 hours of light; highest shade tolerance among warm-season grasses; requires frequent watering (1 inch per week); prefers well-drained sandy soils with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.5 to 4.0 inches; weekly mowing; 2-4 lbs Nitrogen per 1000 sq ft annually; high maintenance due to water and pest needs; requires periodic dethatching.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); susceptible to Chinch bugs and Gray Leaf Spot; poor traffic tolerance.
Ecological Information
Native to coastal Americas; provides good soil stabilization in sandy areas; not considered invasive in native ranges but can dominate locally; often used in residential landscapes to reduce erosion.