St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely indicative of broad-leafed cultivars like Floratam or Palmetto)
Hardiness Zones
USDA Hardiness Zones 8-11. Poor cold tolerance; enters dormant brown state when temperatures drop below 55°F and can suffer winter kill in Zone 7.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It forms a thick sod and typically reaches 6-12 inches if left unmowed. Seed heads are inconspicuous, consisting of a spike-like raceme with seeds embedded in a thick, flattened rachis.
Blade Characteristics
Coarse blade width (8-10mm), flat shape with a distinctively rounded or 'boat-shaped' tip. Vernation is folded in the bud. Ligule is a fringe of short hairs; auricles are absent. The collar is narrow and continuous.
Root System
Moderately deep fibrous root system originating from stolon nodes. High thatch-forming tendency due to stolon density. Establishment is usually via sod or plugs as it rarely produces viable seed.
Growing Information
Origin Region
Native to the coastal areas of the Gulf of Mexico, the Mediterranean, and West Africa; adapted to tropical and subtropical climates.
Growth Habit
Stoloniferous; spreads aggressively via thick above-ground runners (stolons) to form a dense, carpet-like mat.
Sunlight & Water Needs
Partial sun to full sun; one of the most shade-tolerant warm-season grasses (needs 4-5 hours min). High water requirement; moderate drought tolerance but wilts quickly without supplemental irrigation in sandy soils. Prefers pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.5 to 4.0 inches. Requires weekly mowing during peak summer. Fertilization: 2-4 lbs N per 1000 sq ft per year. High maintenance level due to water and pest needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (good for coastal areas). Susceptible to Chinch bugs and Large Patch (fungus). Moderate wear tolerance but slow to recover from heavy traffic.
Ecological Information
Native to coastal regions. Provides soil stabilization and erosion control in sandy coastal soils. Not considered invasive in its native range but can dominate local ecosystems if escaped in tropical climates. Often used as a mono-stand rather than in mixes.