Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
Standard commercial blend types (e.g., 'Midnight', 'Bewitched')
Hardiness Zones
USDA Hardiness Zones 3 through 7; excellent cold tolerance, moderate heat tolerance, goes dormant in extreme summer heat, and performs exceptionally well in northern climates and northern transition zones.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and rich medium to dark green color. Reaches 18 to 24 inches if left unmowed, but maintained at 2 to 3.5 inches. Produces open, pyramid-shaped panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (2-3mm), flat to V-shaped with characteristic boat-shaped tips. Color ranges from medium to dark green or blue-green. Vernation is folded in the bud. Ligule is short and membranous, auricles are absent, and the collar is broad and continuous.
Root System
Moderately deep fibrous root system with extensive underground rhizomes. Forms a dense sod that resists weed invasion. Moderate to high thatch-forming tendency under high maintenance. Medium establishment speed from seed.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and cool temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via aggressive creeping rhizomes to form a dense, uniform turf sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), has moderate to high water needs, moderate drought tolerance (enters dormancy during severe droughts), and prefers well-drained fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches. Requires regular mowing, medium-high fertilization (3-4 lbs N per 1000 sq ft per year), periodic dethatching and core aeration, and is classified as a high-maintenance turf.
Special Characteristics
Exceptional wear tolerance and traffic recovery due to rhizomatous growth. Susceptible to certain diseases like leaf spot, dollar spot, and summer patch. Good cold and winter color retention compared to warm-season grasses.
Ecological Information
Introduced species in North America. Provides good soil stabilization, erosion control, and moderate wildlife value for foraging birds and small mammals. Frequently blended with Perennial Ryegrass and Fine Fescue.