St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Floratam-type (likely non-improved or 'Palmetto' based on coarse texture and opportunistic growth)
Hardiness Zones
USDA Zones 8-11; poor cold tolerance; enters dormancy (turns brown) when soil temperatures drop below 55°F.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It is highly competitive in moist environments and creates a dense sod when well-maintained, though the pictured sample shows significant weed encroachment.
Blade Characteristics
Coarse width (>4mm), flat shape with a distinct boat-shaped or rounded tip; vernation is folded in the bud; ligule is a short fringe of hairs; auricles are absent; collar is constricted.
Root System
Fibrous and relatively shallow compared to Bermuda, but develops deep roots in sandy soils; primarily spreads via thick, creeping stolons; moderate thatch producer.
Growing Information
Origin Region
Coastal regions of North and South America, Africa, and the Caribbean; common in Gulf Coast and Florida.
Growth Habit
Stoloniferous (spreading via aggressive above-ground runners/stolons); forms a thick, carpet-like mat.
Sunlight & Water Needs
Full sun to partial shade (one of the most shade-tolerant warm-season grasses); high water needs; prefers well-drained but moist soils with pH 6.0-7.5.
Mowing & Maintenance
High maintenance; ideal height 2.5-4.0 inches; requires frequent mowing to prevent stolon 'looping'; 2-4 lbs Nitrogen per 1000 sq ft annually; requires regular irrigation.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal areas); poor wear tolerance due to succulent stolons; moderate disease susceptibility (Large Patch, Gray Leaf Spot).
Ecological Information
Introduced/Naturalized in the US; provides soil stabilization in coastal ecosystems; can be invasive in non-native wetland margins; often blended with other warm-season varieties in transition zones.