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
Standard turf blends (commonly mixed with Perennial Ryegrass and Fine Fescue)
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7. Excellent cold tolerance, goes dormant and turns straw-colored during severe winter freezes, and can go into summer dormancy during extended hot, dry spells.
About This Grass
Forms a dense, high-quality, fine to medium-textured turf with rich medium to dark green coloration. Displays excellent self-repairing capabilities due to aggressive spreading rhizomes. Unmowed height reaches 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Blades are medium-narrow (2-4mm), flat to folded with prominent parallel veins and characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system combined with strong rhizomes. Establishes relatively slowly from seed, but forms an exceptionally dense, tough sod once mature, providing great wear resistance and recovery.
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 extensive root stems to form a dense, uniform turf mat
Sunlight & Water Needs
Performs best in full sun, requiring at least 6 hours of direct sunlight daily, though some cultivars have moderate shade tolerance. High water requirements during dry spells to prevent summer dormancy; prefers well-drained, fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height ranges from 2.0 to 3.5 inches. Requires frequent mowing during peak spring and autumn growth periods. Moderate to high maintenance level, needing 3 to 4 lbs of nitrogen per 1000 sq ft annually and periodic dethatching.
Special Characteristics
Exceptional wear tolerance and self-repairing capability via rhizomes. Good cold hardiness and disease resistance, though susceptible to summer patch, dollar spot, and leaf spot if over-fertilized or improperly watered.
Ecological Information
Introduced species widely used for soil stabilization, erosion control on slopes, and residential/commercial turf. Provides minimal direct wildlife food source compared to native prairie grasses, but offers ground cover and integrates well into cool-season lawn mixes.