Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
Common-type or generic improved turf cultivar
Hardiness Zones
Thrives in USDA Hardiness Zones 3 to 7. Excellent cold tolerance, goes semi-dormant or brown in extreme heat without irrigation.
About This Grass
Forms a dense, fine-to-medium textured sod with bright to dark green color. When unmowed, it reaches heights of 18 to 24 inches, producing characteristic pyramidal, open panicle seed heads. Maintained turf is dense and upright.
Blade Characteristics
Blades are medium-fine (2-3 mm wide), flat or folded, with distinct boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, and auricles are absent.
Root System
Fibrous root system with aggressive underground rhizomes. Moderate depth (typically 2-4 inches), moderate to high thatch tendency under high fertilization, and slow to moderate establishment speed from seed.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via slender creeping rhizomes to form a dense, uniform turf sod
Sunlight & Water Needs
Requires full sun (minimum 6 hours direct sunlight), moderate to high water needs for optimal appearance, moderate drought tolerance (enters dormancy during severe droughts), and prefers well-drained loamy soils with pH 6.0-7.0.
Mowing & Maintenance
Ideal mowing height ranges from 2.0 to 3.5 inches. Requires regular mowing, moderate to high fertilization (2-4 lbs N per 1000 sq ft per year), occasional dethatching and aeration, and high maintenance level.
Special Characteristics
Exceptional self-repairing wear tolerance due to rhizomes, good cold tolerance, moderate disease susceptibility (e.g., leaf spot, dollar spot), excellent winter color retention in cooler climates, and forms a tough, durable turf sod.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense rhizomatous root network. Frequently blended with Perennial Ryegrass and Tall Fescue in cool-season turf seed mixes.