St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely 'Floratam' or 'Palmetto' (Commonly cultivated in residential lawns)
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; enters dormancy when temperatures drop below 55°F and may suffer winter kill in Zone 8 without protection.
About This Grass
A coarse-textured, low-growing grass that forms a thick, spongy sod. It maintains a deep green to blue-green color during the growing season and turns brown/dormant in frost conditions. Seed heads are inconspicuous spikes with small seeds embedded in the rachis.
Blade Characteristics
Coarse blade width (>4mm), flat shape with a distinctively rounded or 'boat-shaped' tip. Color is typically medium to dark green. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent.
Root System
Fibrous and moderately deep; primarily spreads through extensive stolons. It has high thatch-forming tendencies and moderate establishment speed from sod or plugs.
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 aggressively via thick, creeping above-ground runners (stolons) to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial Sun to Full Sun; one of the most shade-tolerant warm-season grasses (needs 4-5 hours of sun). High water requirements; requires regular irrigation to prevent wilt. Prefers well-drained, slightly acidic to neutral soils.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4.0 inches. Requires frequent mowing during peak summer growth. Fertilization: 2-4 lbs N per 1000 sq ft per year. High maintenance level due to water and pest needs.
Special Characteristics
Excellent shade tolerance compared to other warm-season grasses; high salt tolerance (good for coastal areas); poor wear/traffic tolerance due to thick stolons being easily crushed.
Ecological Information
Native to coastal regions; excellent for soil stabilization in sandy areas. While not typically invasive in wild lands, it can be aggressive in garden beds. Often host to 'Large Patch' fungus and Chinch bugs.