Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Generic / Common Kentucky Bluegrass (likely a mix with white clover based on image)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance, poor heat tolerance in the Deep South.
About This Grass
A dark green, medium-textured grass with a soft feel. It stays low when mowed and turns brown and dormant during hot, dry summers unless irrigated. Growth is most vigorous in spring and fall.
Blade Characteristics
Boat-shaped (v-shaped) tips, folded in the bud, parallel veins with a prominent 'train track' midrib. Blades are generally 2-4mm wide, dark green to blue-green.
Root System
Moderately shallow fibrous roots combined with extensive underground rhizomes. Slow to germinate (21 days) but excellent sod-forming capability and moderate thatch tendency.
Growing Information
Origin Region
Europe and Northern Asia; well-adapted to Northern US and Canada
Growth Habit
Rhizomatous (spreading underground via rhizomes), forming a dense sod
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance. High water needs; poor drought tolerance compared to fescues, often requiring irrigation to prevent dormancy.
Mowing & Maintenance
Ideal height 2.5 to 3.5 inches; frequent mowing required during peak growth. Fertilization 3-5 lbs N/1000 sq ft/year. High maintenance level.
Special Characteristics
Excellent self-repairing ability via rhizomes; high wear tolerance for foot traffic; very common in sports fields and residential lawns.
Ecological Information
Introduced and naturalized in North America. Provides forage for small mammals and host for various butterfly larvae. Often found growing with Trifolium repens (white clover) as seen in user image.