St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or 'Floratam' type (based on coarse texture)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; becomes dormant and turns brown when temperatures drop below 55°F; prone to winter kill in northern transition zones.
About This Grass
A coarse-textured, low-growing turfgrass with a vibrant medium-to-dark green color. It develops a thick sod that crowds out most weeds. When unmowed, it can reach 6-12 inches, but is typically maintained much lower. Seed heads are spike-like racemes with seeds embedded in a thickened rachis.
Blade Characteristics
Coarse blades (8-10mm wide), folded in the bud (folded vernation), with a distinct rounded or blunt boat-shaped tip. Blades are smooth on both surfaces with a short, fringed, membranous ligule and no auricles.
Root System
Relatively shallow but dense fibrous root system primarily arising from stolon nodes; high thatch-forming tendency; moderate establishment speed from sod or plugs; provides good wear recovery via stolon growth.
Growing Information
Origin Region
Native to coastal regions of the Atlantic Ocean, Gulf of Mexico, and Caribbean; widely adapted to tropical and subtropical climates
Growth Habit
Stoloniferous; spreads rapidly through thick, creeping above-ground runners (stolons) to form a dense, carpet-like mat
Sunlight & Water Needs
Prefers Full Sun but has some of the best shade tolerance among warm-season grasses (needs 4-6 hours); high water requirement; moderate drought tolerance but wilts quickly without moisture; prefers slightly acidic to neutral soil (pH 6.0-7.5).
Mowing & Maintenance
Ideal mowing height is 2.5 to 4.0 inches; requires frequent mowing during peak summer; fertilization 2-4 lbs N per 1000 sq ft per year; high maintenance due to water and pest needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); poor traffic tolerance compared to Bermuda; susceptible to Large Patch (fungus) and Chinch Bugs.
Ecological Information
Native to tropical coastal areas; provides excellent soil stabilization and erosion control; low wildlife food value but provides cover; can be invasive in sensitive wetland margins if escaped from lawns.