Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf, Residential Turf
Variety / Cultivar
Midnight (known for dark green color and dense growth)
Hardiness Zones
USDA Zones 3-7; excellent cold tolerance, moderate heat tolerance; goes semi-dormant during intense summer heat
About This Grass
Forms a dense, high-quality turf with medium-fine texture and rich dark green to blue-green color; grows 18-24 inches if unmowed but maintained at 2-3 inches; produces open, pyramidal panicle seed heads at maturity
Blade Characteristics
Medium-fine width (2-4mm), flat to V-shaped with distinctive boat-shaped tips and parallel sides, folded in the bud (vernation), prominent parallel veins with a light-colored midrib; short membranous ligule, absent auricles
Root System
Moderate to deep fibrous root system with extensive underground rhizomes; moderate establishment speed from seed; forms a very tough, dense sod that resists wear and helps recover from damage
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America, performing best in northern and transition zones
Growth Habit
Aggressively rhizomatous, forming a dense, uniform turf mat and sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) with moderate to high water needs; moderate drought tolerance entering dormancy during severe dry periods; prefers well-drained, fertile loamy soils with pH 6.0-7.0
Mowing & Maintenance
Mow at 2.0 to 3.0 inches every 5-7 days during active growth; high maintenance requiring 3-5 lbs N per 1000 sq ft annually, regular irrigation, aeration, and occasional dethatching
Special Characteristics
High wear and traffic tolerance due to rhizomes; good self-repairing capability; susceptible to certain diseases like leaf spot, dollar spot, and summer patch; excellent erosion control and weed suppression
Ecological Information
Introduced species in North America; provides low wildlife value compared to native prairies; excellent for preventing soil erosion, filtering runoff, and stabilizing residential soils; commonly blended with Perennial Ryegrass and Tall Fescue