Kentucky Bluegrass
Poa pratensis · Cool-season perennial (C3)
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Elite type (e.g., 'Midnight' or 'Baron' typical of home lawns)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance (goes dormant in hot summers); well-suited for northern climates.
About This Grass
Dense, fine-to-medium textured turf with a rich emerald to dark blue-green color. Grows 12-24 inches unmowed; forms a lush carpet when maintained.
Blade Characteristics
Narrow blades (2-4mm), folded in the bud (vernation), featuring a distinct boat-shaped tip and twin 'track' veins along the midrib. Ligule is short and membranous; auricles are absent.
Root System
Moderate depth with extensive rhizomes; forms significant thatch; slow to establish from seed but creates a very strong, self-repairing sod.
Growing Information
Origin Region
Native to Europe, North Asia, and Morocco; widely adapted to cool, humid temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), formings a dense, uniform sod
Sunlight & Water Needs
Full sun preferred (6+ hours); high water requirement (1-1.5 inches/week); enters dormancy during extreme drought; prefers pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; frequent mowing required; high fertility needs (3-5 lbs N per 1000 sq ft/year); needs periodic aeration; high maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot and necrotic ring spot; low shade tolerance; high aesthetic value.
Ecological Information
Introduced/Naturalized in North America; provides forage for various larvae; stabilizes soil effectively; frequently blended with Perennial Ryegrass or Fine Fescue.