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 Elite-type Kentucky Bluegrass (e.g., 'Midnight' or 'Baron' typical characteristics)
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, low-growing turfgrass with a distinct dark green to blue-green color. It maintains a soft texture and uniform appearance. When left unmowed, it reaches 12-24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Fine to medium width (2-4mm), folded in development (folded vernation), smooth texture with a distinct 'boat-shaped' tip. Ligule is short and membranous; auricles are absent.
Root System
Moderately shallow fibrous root system with extensive horizontal rhizomes; forms high thatch; slow to moderate establishment from seed but high wear recovery.
Growing Information
Origin Region
Europe, Northern Asia, and North Africa; now dominant in Northern US and Canada
Growth Habit
Rhizomatous (spreading underground), forming a dense, uniform sod with moderate rate of spread
Sunlight & Water Needs
Full Sun preferred (6+ hours), moderate shade tolerance. High water requirements; enters summer dormancy during extreme drought; prefers pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches; weekly frequency; requires 2-4 lbs Nitrogen per 1000 sq ft annually; high maintenance level including dethatching and core aeration.
Special Characteristics
Excellent traffic tolerance and self-repairing ability via rhizomes; susceptible to leaf spot and necrotic ring spot; moderate salt tolerance.
Ecological Information
Introduced/Naturalized in North America; provides forage for various wildlife; excellent soil stabilizer for erosion control; often blended with Perennial Ryegrass or Fine Fescues.