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 elite cultivar
Hardiness Zones
USDA Hardiness Zones 3-7, performs exceptionally well in northern climates and the northern transition zone.
About This Grass
Dense, fine-to-medium textured turf with a rich dark green to blue-green color. Grows up to 18-24 inches if unmowed, but maintained at 2-3 inches. Features panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (3-4mm), flat with distinct parallel veins, boat-shaped tips, folded in the bud (vernation), short membranous ligule, and no auricles.
Root System
Moderately deep fibrous root system with extensive underground rhizomes. Moderate establishment speed, forms a thick thatch layer if over-fertilized, excellent wear recovery.
Growing Information
Origin Region
Europe and Northern Asia; widely cultivated throughout the northern United States and Canada
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod
Sunlight & Water Needs
Full sun to partial shade (minimum 4-6 hours direct sun). High water needs during dry spells; goes dormant in severe drought and greens up when watered. Prefers well-drained loamy soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal mowing height 2.0 to 3.5 inches. Medium-high maintenance level, requiring regular fertilization (3-4 lbs N per 1000 sq ft per year), periodic aeration, and dethatching.
Special Characteristics
High wear tolerance due to aggressive rhizomes, excellent cold tolerance, moderate disease resistance (susceptible to leaf spot and dollar spot if mismanaged), poor shade tolerance compared to fescues.
Ecological Information
Introduced to North America by European settlers. Excellent for erosion control, soil stabilization, and domestic lawns. Often blended with perennial ryegrass and fine fescues.