Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common or Elite Cultivar (e.g., Midnight, Baron)
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor heat tolerance (enters summer dormancy); best for Northern and Transition Zone regions.
About This Grass
A medium-textured, cool-season grass known for its boat-shaped leaf tips and rich blue-green color. It forms a thick, carpet-like turf that goes dormant in high heat but recovers quickly in autumn.
Blade Characteristics
Blade width is medium (2-4mm); flat to slightly folded; distinctive boat-shaped (keeled) tip; dark green or blue-green color; vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Moderately shallow fibrous root system supported by extensive rhizomes. Forms significant thatch; establishment is slow (2-3 weeks to germinate) but creates a very stable, knit sod.
Growing Information
Origin Region
Native to Europe, North Asia, and Morocco; widely adapted to temperate climates
Growth Habit
Rhizomatous (spreading underground), forming a dense, uniform sod with high regenerative capacity
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) with some shade tolerance; high water needs (1-1.5 inches per week); moderate drought tolerance through dormancy; prefers well-drained soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; frequent mowing needed during spring/fall; 3-5 lbs N per 1000 sq ft annually; requires periodic dethatching and aeration; high maintenance level.
Special Characteristics
Excellent foot traffic/wear tolerance due to rhizomes; susceptible to leaf spot, summer patch, and powdery mildew; good recovery from injury; provides the classic 'manicured' lawn look.
Ecological Information
Introduced and naturalized in North America; provides forage for various grazing animals and nesting material for small birds; highly effective at preventing soil erosion via dense rhizome mats.