Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Unspecified Cultivar (e.g., Baron or Midnight type)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in deep south; goes dormant in winter/extreme summer heat.
About This Grass
A medium-textured turfgrass with a boat-shaped leaf tip. When managed, it forms a thick green carpet; if unmowed, it reaches 12-24 inches with open panicle seed heads. Color ranges from light to deep blue-green.
Blade Characteristics
Width: 2-4mm (medium); Shape: V-shaped or flat; Tip: Boat-shaped (keeled); Color: Blue-green to dark green; Vernation: Folded in the bud; Ligule: Very short, membranous; Auricles: Absent; Collar: Narrow to medium width.
Root System
Moderately shallow fibrous roots with extensive rhizomes; high thatch tendency; slow establishment from seed but forms a dense, durable sod.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; widely adapted to temperate climates globally.
Growth Habit
Rhizomatous (spreading underground); forms a dense sod following establishment via aggressive rhizomes and tillering.
Sunlight & Water Needs
Full Sun preferred (6+ hours); moderate shade tolerance; high water needs (1 inch/week); enters dormancy during severe drought to survive; pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.5-3.5 inches; frequent mowing needed during spring/fall; 2-4 lbs N/1000 sq ft/year; annual aeration and periodic dethatching; High maintenance level.
Special Characteristics
Excellent traffic recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; moderate salt tolerance; boat-shaped tips are a primary identifier.
Ecological Information
Introduced and naturalized in North America; provides forage for various wildlife and stabilizing cover against erosion; often mixed with Fine Fescue and Perennial Ryegrass for biodiversity.