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
General species type (commonly used in mixtures)
Hardiness Zones
USDA Hardiness Zones 3-7; thrives in northern temperate climates with cold winters and moderate summers. Goes into winter dormancy.
About This Grass
Forms a dense, high-quality turf with a vibrant medium to dark green color, fine to medium texture. Unmowed height can reach 18 to 24 inches, typically maintained at 1.5 to 2.5 inches. Produces open, pyramid-shaped panicle seed heads at maturity.
Blade Characteristics
Medium width (2-4mm), flat to folded shape with distinctive boat-shaped tips and prominent parallel veins (tramline effect). Vernation is folded in the bud. Ligule is short and membranous, auricles are absent.
Root System
Fibrous root system with extensive underground rhizomes, moderate depth (4-6 inches). Moderate establishment speed from seed, forms a very dense sod that recovers well from wear via rhizomatous spread, with a moderate thatch-forming tendency.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via aggressive horizontal roots, forming a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily) for best performance, though some cultivars have moderate shade tolerance. High water needs to maintain green color during summer droughts; goes dormant during severe heat and drought. Prefers well-drained, fertile soils with a pH between 6.0 and 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches. Requires regular mowing, high fertilization (3-4 lbs N per 1000 sq ft per year), regular irrigation, and periodic dethatching and aeration. High maintenance level.
Special Characteristics
Good wear tolerance and excellent self-repairing capability due to rhizomes. Moderate to good disease resistance depending on cultivar. Poor shade tolerance compared to fescues. Excellent erosion control when established.
Ecological Information
Introduced species in North America. Provides moderate wildlife habitat and soil stabilization, filters runoff water, and is frequently blended with Perennial Ryegrass and Tall Fescue for lawns and sports turf.