St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass path
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely Florida Common or hybrid type)
Hardiness Zones
USDA Hardiness Zones 8-11. Sensitive to cold; enters dormancy when temperatures drop below 55°F and can suffer winter kill in Zone 7 and below.
About This Grass
A coarse-textured, low-growing grass that forms a thick sod. It maintains a medium-to-dark green color during the growing season and turns brown during winter dormancy. Unmowed height can reach 6-12 inches, with seed heads appearing as small spikes on one side of a flattened rachis.
Blade Characteristics
Coarse blade width (>4mm), folded in the bud (folded vernation), flat with a blunt or rounded boat-shaped tip. Color is light to medium green. Ligule is a fringe of short hairs; auricles are absent; the collar is narrow and distinct.
Root System
Fibrous root system supported by creeping stolons; relatively shallow to moderate depth compared to Bermuda. Slow to establish from seed (usually sodded or plugged); forms significant thatch over time; poor-to-moderate wear recovery.
Growing Information
Origin Region
Native to West Indies, Africa, and the Gulf of Mexico/Caribbean coastal regions; well-adapted to humid subtropical environments
Growth Habit
Stoloniferous (spreads via aggressive above-ground runners); forms a thick, dense mat with moderate to fast spread rates
Sunlight & Water Needs
Partial sun to full sun (requires at least 4-5 hours); recognized as the most shade-tolerant of the warm-season grasses. High water needs; low drought tolerance (wilts quickly without moisture). Prefers well-drained, fertile soils with pH 6.0-7.5.
Mowing & Maintenance
High maintenance. Recommended mowing height: 2.5–4.0 inches. Fertilization: 2-4 lbs Nitrogen per 1,000 sq ft annually. Requires regular dethatching and aeration. High susceptibility to Chinch bugs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); poor traffic tolerance; highly susceptible to Gray Leaf Spot and Large Patch diseases.
Ecological Information
Introduced/Naturalized in the US; excellent for soil stabilization in coastal sandy areas; low wildlife value beyond cover; can be invasive in native wetlands; often grown as a monoculture but can coexist with Centipede grass in some regions.