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 Fairways
Variety / Cultivar
Common or Elite-type Bluegrass (e.g., 'Midnight' or 'Baron' phenotype)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor performance in deep South (Zone 8+); goes dormant after hard frost.
About This Grass
A dense, low-growing turfgrass with a boat-shaped leaf tip. It displays a rich emerald to dark blue-green color. It spreads slowly but forms a very tight, uniform surface once established.
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or flat; distinctive boat-shaped (keeled) tip; dark green to blue-green color; vernation is folded in the bud; ligule is very short (0.2-0.6mm) and membranous; auricles are absent.
Root System
Moderately shallow fibrous root system supported by vigorous rhizomes; high thatch-forming tendency; slow establishment from seed (21+ days) but forms high-tensile sod.
Growing Information
Origin Region
Native to Europe, North Asia, and mountains of Morocco; widely naturalized across temperate North America
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, sod-forming mat
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance; high water requirements (1-1.5 inches per week); enters summer dormancy during severe drought to survive.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches; high maintenance level; requires 2-4 lbs Nitrogen per 1000 sq ft annually; needs periodic dethatching due to rhizome buildup.
Special Characteristics
Excellent wear tolerance and self-repairing ability via rhizomes; susceptible to summer patch, necrotic ring spot, and dollar spot; very soft texture underfoot.
Ecological Information
Introduced in North America; provides soil stabilization via dense rhizome network; common companion to Perennial Ryegrass and Fine Fescue in turf mixes.