St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Palmetto' St. Augustine (known for excellent shade tolerance and semi-dwarf growth habit)
Hardiness Zones
Thrives in USDA Hardiness Zones 8 through 10. Sensitive to hard freezes and goes dormant in the cooler parts of its range. Does not tolerate severe frost well.
About This Grass
Forms a dense, coarse-textured, blue-green to dark green carpet. Unmowed height reaches 6 to 12 inches, while maintained turf is kept at 2 to 3.5 inches. Produces flat, upright seed heads (spikes) on a flattened rachis at maturity.
Blade Characteristics
Coarse texture with flat blades measuring 4 to 10 mm in width. Blunt, rounded to slightly pointed tips. Folded vernation in the bud. Prominent midvein with a membranous ligule consisting of a fringe of hairs. Continuous collar region without prominent auricles.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Establishes quickly via sod or plugs. Moderate to high thatch-forming tendency under high fertility and moisture. Moderate drought tolerance with rapid recovery when watered.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal regions of the Americas, and parts of Africa. Widely cultivated in the southern United States, particularly Florida and the Gulf Coast.
Growth Habit
Aggressively stoloniferous, spreading via thick, above-ground runners (stolons) that form a dense, coarse turf mat.
Sunlight & Water Needs
Requires full sun to moderate shade (more shade-tolerant than most warm-season grasses). Needs regular watering, requiring about 1 inch of water per week. Good drought tolerance through dormancy, but prefers consistently moist soils.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches. Mowed every 5 to 7 days during active growing season. Requires 2 to 4 lbs of nitrogen per 1000 sq ft annually. Medium to high maintenance level due to thatch management and pest susceptibility.
Special Characteristics
Moderate to low traffic tolerance compared to Bermuda or Zoysia. Susceptible to chinch bugs, sod webworms, and large patch fungus. Excellent salt tolerance, making it ideal for coastal lawns. Poor cold tolerance.
Ecological Information
Introduced/cultivated across the American coastal tropics and subtropics. Provides good soil stabilization and erosion control in sandy coastal soils. Limited wildlife forage value compared to native grasses, but forms protective ground cover.