St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' based on blade width and spacing
Hardiness Zones
USDA Zones 8-11. Excellent heat tolerance; poor cold tolerance (turns brown/dormant quickly after first frost).
About This Grass
A coarse-textured, low-growing grass that forms a dense, blue-green turf. It remains relatively low to the ground but can reach 6-12 inches if unmowed. Seed heads are inconspicuous spikes with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse blades (8-10mm wide), flat, with a distinct rounded or 'boat-shaped' tip. Color is typically deep green to blue-green. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent.
Root System
Moderately deep fibrous root system originating from nodes on stolons. Fast establishment via sod or plugs. High thatch-forming tendency due to stolon density.
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 aggressive above-ground runners); creates a thick, carpet-like mat
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses). Needs 4-6 hours of sun. Requires moderate to high watering; poor drought tolerance compared to Bermuda grass.
Mowing & Maintenance
Ideal height 2.5–4.0 inches. Frequency is weekly during peak summer. Fertilization: 2-4 lbs N per 1000 sq ft per year. High maintenance due to water and pest needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas); poor wear/traffic tolerance due to succulent stolons; susceptible to Chinch bugs and Gray Leaf Spot.
Ecological Information
Introduced/Naturalized in many regions. Provides soil stabilization in sandy coastal areas. Not considered invasive in managed landscapes but can crowd out native groundcovers in humid forests.