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' or common St. Augustine, noted for coarse texture and blue-green color
Hardiness Zones
USDA Hardiness Zones 8 through 10, with some varieties performing well in the warmer parts of Zone 7. Highly sensitive to freezing temperatures and enters dormancy when temperatures drop below 50 degrees Fahrenheit.
About This Grass
Forms a thick, carpet-like turf with coarse, flat blades and a creeping growth habit. It grows aggressively via stolons, creating a dense sod that crowds out many weeds. Color ranges from blue-green to dark green during the growing season, turning brown or straw-colored when dormant in cooler winter temperatures.
Blade Characteristics
Blades are coarse, flat, and wide (greater than 4mm), with rounded tips. Vernation is folded in the bud. The ligule is a fringe of hairs, and auricles are absent. The collar region is continuous.
Root System
Moderately deep fibrous root system combined with aggressive surface stolons. Moderate thatch-forming tendency, fast establishment from sod or plugs, and good sod-forming ability with fair wear recovery.
Growing Information
Origin Region
Native to the Gulf of Mexico region, coastal areas of the southeastern United States, and the Caribbean; widely adapted to tropical and subtropical regions worldwide
Growth Habit
Stoloniferous, spreading rapidly via thick surface runners above ground to form a dense, coarse turf mat
Sunlight & Water Needs
Requires full sun to partial shade (more shade-tolerant than many other warm-season grasses, needing at least 4 hours of direct sunlight). High water needs during establishment and active growth; moderate drought tolerance as it enters dormancy during severe dry spells. Prefers moist, fertile soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height ranges from 2.5 to 4 inches using a rotary mower. Mowing frequency is weekly during peak growing season. Fertilization needs are moderate to high (2 to 4 lbs N per 1000 sq ft per year). Requires periodic dethatching and core aeration. Maintenance level is medium.
Special Characteristics
Moderate traffic and wear tolerance (lower than Bermuda or Zoysia), susceptible to chinch bugs, sod webworms, and take-all root rot. Good salt tolerance, making it popular in coastal regions. Excellent shade tolerance relative to other warm-season turfgrasses.
Ecological Information
Introduced and naturalized in tropical and subtropical regions. Provides low to moderate wildlife habitat value, primarily serving as ground cover. Excellent for erosion control on coastal soils and slopes. Does not typically act as an aggressive invasive weed in natural ecosystems outside of managed landscapes.