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
Standard turf blends, cultivars like 'Midnight' or 'Gallagher'
Hardiness Zones
USDA Zones 3-7, excellent cold tolerance down to -30F or lower, struggles in extreme summer heat unless irrigated, goes dormant in winter freeze.
About This Grass
Medium-fine texture, rich blue-green to dark green color, forms a dense and durable carpet, grows 1.5 to 2.5 inches when maintained, reaches up to 18-24 inches if unmowed with open, pyramidal panicle seed heads.
Blade Characteristics
Blade width 2-4mm, folded in the bud (vernation), boat-shaped tips, prominent parallel veins with a slight central groove creating a tramline appearance, membranous ligule, and no auricles.
Root System
Moderately deep fibrous root system with extensive rhizomes, moderate to high thatch-forming tendency, slow to medium establishment from seed, excellent wear recovery through spreading rhizomes.
Growing Information
Origin Region
Europe and Northern Asia, widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense, uniform turf mat and sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high water needs, enters summer dormancy during severe drought, prefers well-drained fertile loam with pH 6.0 to 7.0.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches, frequent mowing during peak spring/fall growth, requires 3-5 lbs N per 1000 sq ft annually, moderate to high maintenance level, occasional dethatching and core aeration needed.
Special Characteristics
Exceptional wear tolerance and self-repairing capability via rhizomes, good cold tolerance, moderate shade tolerance, susceptible to patch diseases and rust under high humidity, excellent for home lawns and sports fields.
Ecological Information
Introduced species in North America, provides good soil stabilization and erosion control, standard component of northern turf seed mixes, moderate wildlife value for grazing.