St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass path
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine / Floratam (Likely based on coarse texture)
Hardiness Zones
USDA Zones 8-11. Excellent heat tolerance; poor cold tolerance. Becomes dormant and turns brown when soil temperatures drop below 55°F; prone to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing turfgrass with a deep blue-green to emerald green color. It forms a thick carpet that crowds out weeds. Unmowed, it can reach 6-12 inches; maintained, it is dense with thick, fleshy stolons. Seed heads are inconspicuous spikes with seeds embedded in one side of the rachis.
Blade Characteristics
Coarse blade width (>4mm), flat shape with a distinct boat-shaped or rounded-blunt tip. Vernation is folded in the bud. Color is medium to dark green. The ligule is a fringe of short hairs; auricles are absent; the collar is continuous and constricted.
Root System
Fibrous and moderately deep, primarily originating from nodes along the stolons. It has a high thatch-forming tendency and moderate establishment speed from sod or plugs. Dense sod formation provides good wear recovery but poor drought dormancy.
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), forming a dense, coarse mat
Sunlight & Water Needs
Partial sun to full sun (4-6 hours minimum); better shade tolerance than most warm-season grasses. High water needs; requires regular irrigation during dry spells. Prefers well-drained, fertile soils with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.5 to 4.0 inches. Frequency: weekly during peak growth. Fertilization: 2-4 lbs N per 1000 sq ft per year. High maintenance due to irrigation and pest monitoring (Chinch bugs).
Special Characteristics
Excellent salt tolerance (ideal for coastal areas), best-in-class shade tolerance for warm-season grasses, poor traffic tolerance compared to Bermuda, susceptible to SAD (St. Augustine Decline) virus and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in the US. Provides soil stabilization in sandy coastal areas. Low wildlife value except for cover. Can be aggressive in manicured landscapes but is not typically considered a wildland invasive.