Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae (the Grass family), Subfamily Pooideae
Grass Category
Lawn, Turf, and Sports Grass
Variety / Cultivar
Generic Kentucky Bluegrass (potential mix with Fine Fescue)
Hardiness Zones
USDA Zones 2-7; highly cold-tolerant but struggles in the humid heat of the Deep South.
About This Grass
A smooth, upright perennial grass that forms a high-density, lush turf. It is deep green to blue-green in color. When unmowed, it can reach 12-24 inches with a pyramid-shaped open panicle seed head. It exhibits a soft, fine-to-medium texture.
Blade Characteristics
Fine to medium width (2-4mm), dark green, with a distinctive boat-shaped (keeled) tip. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent. The blade face has a prominent central dual-vein (track) down the center.
Root System
Deeply fibrous root system complemented by strong rhizomes. Highly thatch-forming if not managed. Moderate establishment speed compared to ryegrass, but creates superior sod strength and durability.
Growing Information
Origin Region
Europe, North Asia, and Northern Africa; now widespread across North America especially across the northern United States and Canada
Growth Habit
Rhizomatous (spreads via underground tillers); creates a dense, thick sod which can fill in bare spots over time
Sunlight & Water Needs
Prefers full sun (minimum 6-8 hours); moderate shade tolerance. Requires consistent moisture (1 inch of water per week) and has moderate drought tolerance (enters dormancy during extreme heat/drought).
Mowing & Maintenance
Ideal mowing height is 2.5 to 3.5 inches. High maintenance level requiring regular fertilization (3-5 lbs of Nitrogen per 1000 sq ft annually) and periodic aeration or dethatching to manage the sod layer.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomatous growth. Susceptible to summer patch, necrotic ring spot, and powdery mildew in shade. Strong winter hardiness and beautiful dark color.
Ecological Information
Introduced naturalized species in North America. Provides significant erosion control through dense sod formation. High forage value for livestock and provides cover for small mammals and food for various lepidoptera larvae.