St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-like variety (characterized by coarse texture and purple/green stolons)
Hardiness Zones
USDA Hardiness Zones 8-11. Excellent heat tolerance but poor cold tolerance; will go dormant and turn brown when temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing turfgrass that forms a thick, spongy sod. It maintains a deep green to blue-green color during the growing season and turns brown during winter dormancy. Unmowed, it can reach 6-12 inches, but it is typically maintained as a dense lawn.
Blade Characteristics
Coarse blades (>4mm width), flat with a rounded or blunt tip. Color is dark green to blue-green. Vernation is folded in the bud. The ligule is a short fringe of hairs, and auricles are absent. The collar is continuous and somewhat constricted.
Root System
Fibrous and moderately deep; primarily spreads through vigorous stolons. It has a high thatch-forming tendency 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 via thick above-ground runners (stolons) that root at nodes to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial sun to full sun (needs 4-6 hours minimum); better shade tolerance than most warm-season grasses. High water needs; requires regular irrigation during dry periods to prevent wilt.
Mowing & Maintenance
Mowing height of 3.0-4.0 inches; weekly frequency. Fertilization: 2-4 lbs N per 1000 sq ft per year. High maintenance level due to water and pest requirements.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); poor traffic tolerance; susceptible to Chinch Bugs and Large Patch (fungus).
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization for coastal sandy soils; non-invasive in most upland ecosystems but can displace native coastal vegetation if unmanaged.