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-type (likely a non-dwarf, wide-bladed variety based on coarse texture)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy and turns tan/brown when temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a vibrant green color. It forms a thick sod via thick stolons. If left unmowed, it can reach 6-12 inches; maintained, it looks dense and carpet-like with compressed, spike-like seed heads.
Blade Characteristics
Coarse width (>4mm), folded in the bud (vernation), with a rounded or blunt tip. Color varies from medium to dark green. Features a short, fringed hair ligule and no auricles. Blades are offset at nearly 90 degrees from the stem.
Root System
Fibrous and moderately deep; primarily spreads through thick, fleshy stolons that take root at nodes. Fast establishment speed; moderate thatch tendency and good wear recovery due to stolon growth.
Growing Information
Origin Region
Native to coastal regions of the Caribbean, Gulf of Mexico, and West Africa; best in humid, subtropical climates
Growth Habit
Stoloniferous (spreads by vigorous above-ground runners), forming a dense, thick mat
Sunlight & Water Needs
Partial Sun to Full Sun (one of the most shade-tolerant warm-season grasses); needs 4-6 hours of sun. Requires moderate to high watering; poor drought tolerance compared to Bermuda grass.
Mowing & Maintenance
Ideal height 2.5–4.0 inches; weekly frequency. Requires 2-4 lbs Nitrogen per 1000 sq ft annually. High maintenance level due to water needs and susceptibility to Chinch bugs.
Special Characteristics
High salt tolerance (excellent for coastal areas), best-in-class shade tolerance for warm-season grass, poor traffic tolerance due to fleshy stolons being easily crushed.
Ecological Information
Introduced/Naturalized in US; provides soil stabilization in sandy coastal areas. Not considered highly invasive in managed landscapes but can crowd out weaker grasses. Low wildlife food value but provides cover.