Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
'Midnight' or similar dark-green hybrid cultivars
Hardiness Zones
USDA Zones 3 through 7, highly cold tolerant, exhibits summer dormancy in hot southern transition zones
About This Grass
Forms a dense, high-quality turf with medium-fine texture and rich dark green to blue-green color; maintains color well in cool weather but enters summer dormancy if drought-stressed; reaches 18 to 24 inches if unmowed, typically maintained at 1.5 to 2.5 inches
Blade Characteristics
Medium-fine width (3-4 mm), flat to V-shaped blades with distinctive boat-shaped tips, prominent parallel veins, folded vernation in the bud, short membranous ligule, and no auricles
Root System
Moderately deep fibrous root system combined with aggressive rhizomes, forming a strong, dense sod; moderate establishment speed from seed; prone to moderate thatch build-up over time
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and cool temperate regions worldwide
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily); medium to high water needs for optimal appearance, enters dormancy under severe drought; prefers well-drained fertile soils with a pH of 6.0 to 7.0
Mowing & Maintenance
Ideal mowing height between 1.5 and 2.5 inches; requires regular mowing and fertilization (3-4 lbs N per 1,000 sq ft annually); moderate to high maintenance level with occasional dethatching and aeration needed
Special Characteristics
Excellent wear tolerance and superior self-repairing capability via rhizomes; moderate shade tolerance; good cold and winter hardiness; susceptible to certain diseases like dollar spot and leaf spot under high humidity
Ecological Information
Introduced species in North America; excellent soil stabilization and erosion control due to dense rhizomatous root network; commonly blended with Perennial Ryegrass and Fine Fescues for home lawns and sports fields