Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Generic / Common Kentucky Bluegrass (cultivars like 'Midnight' or 'Baron' often exhibit darker green color)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance, poor heat tolerance in the Deep South.
About This Grass
A medium-textured turfgrass that produces a lush, dense carpet. It showcases a rich green to blue-green color and grows 12–24 inches if left unmowed. In an ornamental state, it produces panicle-type seed heads that are pyramid-shaped.
Blade Characteristics
Fine to medium width (2-4mm), V-shaped or flat, distinguished by a unique boat-shaped tip. Vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous; moderately deep roots for a cool-season grass. High thatch tendency due to rhizome production; slow to establish from seed but excellent at self-repairing thin spots via rhizomes.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; best adapted to cool, humid climates in North America.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, sod-building mat.
Sunlight & Water Needs
Full sun preferred (at least 6 hours); poor shade tolerance compared to fescues. Requires moderate to high watering; goes dormant during extended drought but recovers well.
Mowing & Maintenance
Ideal height 2.0–3.5 inches. High maintenance level requiring 2-4 lbs of Nitrogen per 1000 sq ft annually. Regular aeration recommended to manage thatch.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot and dollar spot; low salt tolerance; high-quality appearance makes it the 'gold standard' for home lawns.
Ecological Information
Introduced and naturalized in North America; provides forage for various wildlife and stabilizing cover against erosion. Often paired with Perennial Ryegrass or Fine Fescue in mixes.