Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Standard common and improved turf cultivars (e.g., 'Midnight', 'Bewitched')
Hardiness Zones
Thrives in USDA Hardiness Zones 3 to 7, well-suited for northern climates and the northern transition zone. Excellent cold tolerance and winter hardiness; goes dormant in extreme summer heat or drought.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and a rich medium to dark green or blue-green color. Mown height typically maintained at 1.5 to 2.5 inches, while unmowed height can reach 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Blades are medium width (2-4mm), flat to folded with distinct parallel veins and characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Moderate depth fibrous root system with extensive aggressive rhizomes. High thatch-forming tendency under high maintenance. Slow to moderate establishment speed from seed, but excellent self-repairing wear recovery.
Growing Information
Origin Region
Europe, northern Asia, and the mountains of North America; widely cultivated throughout cool-temperate regions worldwide
Growth Habit
Rhizomatous and aggressive spreading habit, forming a dense, uniform sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) with moderate to high water needs. Good drought dormancy tolerance, reviving when moisture returns. Prefers well-drained, fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 1.5 to 2.5 inches. High maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft annually), frequent mowing during peak seasons, and periodic dethatching and aeration.
Special Characteristics
Exceptional wear tolerance and self-repairing capabilities due to rhizomes. Good cold tolerance and winter color retention in milder cool regions. Susceptible to certain diseases like dollar spot and leaf spot under stress.
Ecological Information
Introduced species in North America widely naturalized. Excellent soil stabilization and erosion control due to dense root and rhizome matrix. Frequently blended with perennial ryegrass and fine fescues for lawns.