Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Standard mix (appears similar to 'Midnight' or 'Baron' based on dark green hue)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance (goes dormant above 85-90°F without irrigation).
About This Grass
A medium-textured turf grass that forms a lush, carpet-like lawn. It features a rich emerald to dark blue-green color and produces branched, panicle seed heads when left unmowed.
Blade Characteristics
Blade width: 2-4mm (medium); flat or slightly V-shaped; distinctive boat-shaped (folded) tip; dark green color; folded vernation; very short membranous ligule; auricles absent.
Root System
Moderately shallow fibrous roots combined with extensive horizontal rhizomes; forms thick thatch; slow to moderate establishment from seed but creates high-density sod.
Growing Information
Origin Region
Europe, Northern Asia, and North Africa; now dominant in Northern US and Canada
Growth Habit
Rhizomatous (spreading underground via rhizomes), forming a dense, self-repairing sod
Sunlight & Water Needs
Full Sun (prefers 6+ hours); moderate to high water needs; enters dormancy during severe drought; prefers well-drained, fertile soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height: 2.0-3.5 inches; frequent mowing required in spring/fall; 3-5 lbs N per 1000 sq ft annually; high maintenance level; requires periodic dethatching.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; cold-hardy; susceptible to summer patch, necrotic ring spot, and dollar spot; high aesthetic quality.
Ecological Information
Introduced/Naturalized in North America; provides cover for small insects and soil stabilization; often mixed with Fine Fescue or Perennial Ryegrass for biodiversity.