St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
'Floratam', a widely planted cultivar known for its coarse texture, blue-green color, and resistance to St. Augustine Decline (SAD) virus.
Hardiness Zones
USDA Hardiness Zones 8 through 10. Sensitive to freezing temperatures and enters dormancy when temperatures drop consistently below 50°F.
About This Grass
Forms a dense, coarse-textured turf with flat blades and blunt tips. Unmowed height can reach 6 to 12 inches, but it is typically maintained much lower. Color ranges from light green to a deep blue-green, going dormant and turning straw-brown in winter under frost conditions.
Blade Characteristics
Coarse blades, typically 4 to 10 mm wide, flat with rounded, boat-shaped tips. Vernation is folded in the bud. The ligule is a fringe of hairs, auricles are absent, and the collar is continuous and broad.
Root System
Moderately deep fibrous root system originating from nodes along the stolons. Forms a heavy thatch layer quickly if over-fertilized or over-watered. Establishes rapidly from sod or plugs.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, the Caribbean, and along the Mediterranean. Well-adapted to tropical and subtropical climates globally, particularly the southern United States.
Growth Habit
Aggressively stoloniferous, forming a thick, dense, carpet-like mat through above-ground runners (stolons).
Sunlight & Water Needs
Requires full sun to partial shade; St. Augustine is the most shade-tolerant of the warm-season grasses. Moderate to high water needs; susceptible to drought stress and goes into dormancy or wilts quickly without adequate moisture.
Mowing & Maintenance
Ideal mowing height is 2.5 to 4 inches using a sharp rotary mower. High maintenance level requiring frequent mowing during peak growing season, regular irrigation, and moderate to high nitrogen fertilization (2 to 5 lbs N per 1000 sq ft annually).
Special Characteristics
Fair to good shade tolerance compared to other warm-season turfgrasses, moderate salt tolerance (making it popular in coastal areas), poor traffic and wear tolerance, and slow recovery from heavy damage.
Ecological Information
Introduced and naturalized in tropical and subtropical regions. Excellent for soil stabilization and erosion control in coastal regions. Provides low wildlife habitat value as a monoculture lawn. Can be invasive in native tropical ecosystems if escaped from cultivation.