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
Common blend varieties (e.g., 'Midnight', 'Bewitched')
Hardiness Zones
Thrives in USDA Hardiness Zones 3-7, with good cold tolerance down to -40F. Can struggle in extreme summer heat unless irrigated, making it common in northern regions and the northern transition zone.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and a rich dark green to blue-green color. Reaches up to 18-24 inches if unmowed, but maintained at 2-3 inches. Features a boat-shaped tip and produces open panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (2-3mm), folded in the bud (vernation), with distinctive boat-shaped tips and parallel veins. Smooth texture with a prominent midrib and distinct tramline lines. Ligule is short and membranous, with no auricles.
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes. Moderate establishment speed, forms a dense sod, and exhibits a moderate to high 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 creeping roots, forming a dense and uniform turf mat
Sunlight & Water Needs
Performs best in full sun (minimum 6 hours of direct sunlight), with moderate to high water requirements. Good cold drought tolerance via summer dormancy, but prefers consistent moisture and well-draining soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches. Requires regular mowing, moderate to high fertilization (3-4 lbs N per 1000 sq ft per year), periodic dethatching, and aeration. Overall maintenance level is Medium-High.
Special Characteristics
Excellent wear tolerance and self-repairing capability due to rhizomes. Good winter color retention in cooler climates, highly resistant to cold temperatures, moderate shade tolerance, and forms a dense barrier against weeds.
Ecological Information
Introduced species in North America. Provides good soil stabilization, erosion control, and moderate wildlife value. Frequently blended with perennial ryegrass and fine fescues for home lawns and sports fields.