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 (widely used cultivar known for its coarse texture, blue-green color, and resistance to St. Augustine Decline virus)
Hardiness Zones
USDA Hardiness Zones 8 through 10 (and warm parts of 11). Excellent heat tolerance, poor cold tolerance (susceptible to damage below freezing), enters winter dormancy and loses color in the northern parts of its range.
About This Grass
Forms a dense, lush carpet with a coarse texture and bright to blue-green color. When left unmowed it can grow 6 to 12 inches tall, but it is typically maintained at a low height of 2 to 3.5 inches. Produces flat, upright seed heads on a spike-like panicle at maturity.
Blade Characteristics
Coarse blades greater than 4mm wide (typically 5-10mm), flat with blunt, rounded tips. Folded vernation in the bud. Smooth texture with prominent parallel veins. Ligule is a fringe of hairs, auricles are absent, and the collar region is continuous.
Root System
Moderate to deep fibrous root system combined with vigorous surface stolons. Tends to produce moderate thatch under high fertilization. Establishes relatively quickly from sod or plugs. Forms a dense turf mat that offers good weed suppression.
Growing Information
Origin Region
Native to tropical and subtropical regions along the Gulf of Mexico, the Caribbean, and coastal areas worldwide; performs best in humid subtropical climates
Growth Habit
Stoloniferous, spreading aggressively via above-ground runners (stolons) to form a thick, coarse sod
Sunlight & Water Needs
Performs best in full sun but has the best shade tolerance among warm-season turfgrasses, requiring a minimum of 4 hours of direct sunlight. High watering needs, especially during establishment and dry periods; moderate drought tolerance by going into dormancy under severe water stress. Prefers moist, well-draining soils with a pH of 6.0 to 7.5.
Mowing & Maintenance
Ideal mowing height is 2.5 to 3.5 inches using a sharp rotary mower to prevent tearing the wide blades. High maintenance level requiring regular irrigation, frequent mowing during peak growing season, and heavy fertilization (4-6 lbs N per 1000 sq ft annually). Periodic dethatching and core aeration may be necessary.
Special Characteristics
Moderate wear and traffic tolerance, lower than Bermuda or Zoysia, but recovers well via stolons. Susceptible to chinch bugs, sod webworms, and fungal diseases like take-all root rot and brown patch. Good salt tolerance, making it popular in coastal regions. Poor cold tolerance.
Ecological Information
Introduced and naturalized in many coastal tropical regions. Provides habitat and cover for various insects and small ground-dwelling wildlife. Excellent for coastal soil stabilization and erosion control due to its dense stoloniferous network. Typically grown as a monoculture lawn.