Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or early-stage cultivars (e.g., 'Midnight' or 'Kenblue'); specimen shows young emergent growth.
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters dormancy during extreme heat or drought; well-suited for northern climates.
About This Grass
A fine-to-medium textured grass with a characteristic dark blue-green color. In the provided image, it is in its early emergence stage, displaying a vibrant green color and upright growth. It is highly valued for its ability to form a thick, self-repairing mat.
Blade Characteristics
Narrow to medium width (2-4mm); V-shaped or flat; distinctive boat-shaped (keeled) leaf tips; folded vernation in the bud; smooth texture with a prominent center vein; ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system complemented by extensive rhizomes. It has a high thatch-forming tendency and slow initial establishment from seed but excellent wear recovery once established.
Growing Information
Origin Region
Europe, Northern Asia, and North Africa; now common across Northern US and Canada.
Growth Habit
Rhizomatous (spreading underground); forms a dense, uniform sod over time.
Sunlight & Water Needs
Prefers Full Sun (6+ hours) but can tolerate partial shade; high water requirement during summer; moderate drought tolerance through dormancy; prefers well-drained soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches; high maintenance; requires 2-4 lbs Nitrogen per 1000 sq ft annually; needs regular aeration/dethatching due to rhizome spread.
Special Characteristics
Excellent traffic tolerance and recovery; susceptible to leaf spot, melting out, and necrotic ring spot; moderate salt tolerance; poor shade tolerance compared to fescues.
Ecological Information
Introduced and naturalized in North America; provides forage for livestock and wildlife; excellent for soil erosion control due to dense sod formation; often mixed with Perennial Ryegrass or Fine Fescue.