St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common Floratam type or Raleigh (indicated by coarse texture and purplish-green stolons)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing turf with a creeping growth habit. It features thick, succulent stolons that root at nodes. It remains dark green in heat but goes dormant and turns tan/brown in freezing temperatures.
Blade Characteristics
Coarse blade width (>4mm), folded vernation, blunt or rounded 'boat-shaped' tips. Blades are typically dark green, smooth on both surfaces, with a short, fringed membranous ligule and no auricles. The collar is broad and continuous.
Root System
Fibrous and relatively shallow to moderately deep; relies heavily on stolon establishment; high thatch tendency due to thick organic accumulation; slow to moderate recovery from heavy wear.
Growing Information
Origin Region
Native to coastal regions of the Gulf of Mexico, Caribbean, and Mediterranean; widely used in Southern US and tropical climates.
Growth Habit
Stoloniferous (spreads entirely by above-ground runners); creates a thick, dense mat but does not produce underground rhizomes.
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses); needs at least 4-5 hours of sun. Requires moderate to high watering; poor drought tolerance compared to Bermuda but prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.5–4.0 inches; weekly mowing frequency; requires 2-4 lbs Nitrogen per 1000 sq ft annually; high maintenance due to potential for thick thatch and susceptibility to pests.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); susceptible to Chinch bugs and Large Patch (Rhizoctonia). Poor traffic tolerance due to coarse, succulent stolons.
Ecological Information
Introduced/Naturalized in many regions; provides soil stabilization in sandy coastal areas; low wildlife value in managed lawn settings; can be invasive in native riparian zones of transition climates.