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
Common or elite blend (such as 'Midnight' or 'Bewitched')
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7. Excellent cold tolerance, but struggles with extreme summer heat unless irrigated. Suitable for the northern half of the transition zone.
About This Grass
Forms a lush, dense, fine-to-medium textured turf with a rich blue-green to dark green color. It has a high density and moderate growth rate, reaching 18 to 24 inches if unmowed, but maintained at 1.5 to 2.5 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium-narrow (2-4mm wide), flat or folded, with characteristic boat-shaped tips. Vernation is folded in the bud. Color ranges from medium to dark blue-green. Features distinct parallel veins and a prominent light-colored midvein with a smooth texture.
Root System
Moderately deep fibrous root system connected by aggressive rhizomes. Forms a very tough, dense sod. Moderate to slow establishment speed from seed, but excellent long-term persistence and self-repairing wear recovery.
Growing Information
Origin Region
Native to Europe, Northern Asia, and parts of the mountains of North America; cultivated worldwide in temperate regions.
Growth Habit
Rhizomatous, forming dense, interconnected sod via underground creeping stems.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for optimal performance; moderate shade tolerance. High watering needs to maintain green color during dry periods; goes into summer dormancy (turning brown) during severe drought. Prefers well-drained fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches. Requires frequent mowing during peak spring/fall growth. High fertilizer requirement (3-4 lbs N per 1000 sq ft annually). Moderate to high maintenance level, including regular aeration and dethatching due to dense thatch buildup.
Special Characteristics
Excellent wear tolerance and traffic recovery due to rhizomes. Good winter color retention in milder northern zones. Moderate drought recovery capability via underground rhizomes. Susceptible to diseases like leaf spot, dollar spot, and summer patch under stress.
Ecological Information
Introduced species in North America for turf use. Provides good soil stabilization and erosion control through dense sod formation. Filters runoff water effectively. Often blended with Perennial Ryegrass and Fine Fescues to improve disease resistance and establishment speed.