Kentucky Bluegrass
Poa pratensis · Cool-season (C3), Perennial
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Fairways
Variety / Cultivar
Common or Elite Cultivars (e.g., 'Midnight', 'Arcadia', or 'Merion')
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; goes dormant in winter/extreme summer heat.
About This Grass
A dense, high-quality turf grass known for its lush green to dark blue-green color. It forms a thick carpet that feels soft underfoot. If unmowed, it reaches 12-24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or folded vernation; distinctive boat-shaped (keeled) leaf tips; smooth blades with a clear center vein (twin midribs); ligule is short and membranous; auricles are absent.
Root System
Relatively shallow fibrous root system supplemented by strong rhizomes; helps form thick sod and provides moderate recovery from wear; prone to thatch buildup over time.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Algeria and Morocco; naturalized throughout North America
Growth Habit
Rhizomatous (underground spreading) forming a dense, durable sod; slow to moderate rate of spread
Sunlight & Water Needs
Prefers Full Sun (6+ hours); moderate shade tolerance; requires regular watering (1 inch per week); enters summer dormancy during severe drought to survive.
Mowing & Maintenance
Maintain at 2.0 to 3.5 inches; frequent mowing required during spring/fall; requires 2-4 lbs Nitrogen per 1000 sq ft annually; aeration and dethatching are occasionally necessary; high maintenance level.
Special Characteristics
Self-repairing through rhizomes; excellent winter hardiness; moderate wear tolerance; susceptible to dollar spot, leaf spot, and summer patch; highly valued for aesthetics.
Ecological Information
Introduced and naturalized in North America; provides forage for livestock and wildlife (deer, rabbits); excellent soil stabilization; often blended with Perennial Ryegrass or Fine Fescue for diversification.