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 Cultivar (e.g., 'Midnight', 'Mazama', or 'Kenblue')
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor heat tolerance in the deep South; performs best in northern climates and high altitudes.
About This Grass
A dense, upright-growing turfgrass with a soft texture and rich emerald to blue-green color. It becomes dormant in extreme heat or drought and goes dormant (browns) in heavy winter frost.
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 short and membranous; auricles are absent.
Root System
Relatively shallow fibrous root system supplemented by an extensive network of rhizomes; high thatch-forming tendency; slow establishment from seed but forms a very dense sod.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Algeria and Morocco; widely adapted to temperate climates globally
Growth Habit
Rhizomatous (spreading underground via rhizomes), forming a dense, self-repairing sod
Sunlight & Water Needs
Full sun preferred (6-8 hours); moderate to high water needs; moderate drought tolerance (enters dormancy as a survival mechanism); prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; high maintenance level; requires 3-5 lbs of Nitrogen per 1000 sq ft annually; requires periodic dethatching and core aeration.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; high aesthetic quality; good disease resistance in modern cultivars (e.g., against leaf spot and melting out); goes dormant to survive stress.
Ecological Information
Introduced and naturalized in North America; provides cover for small mammals; stabilizing for soil in temperate regions; often blended with Perennial Ryegrass or Fine Fescue for genetic diversity.