Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf, Sports Turf, Golf Course Grass
Variety / Cultivar
Common or Turf-type (e.g., 'Midnight', 'Baron', or 'Kenblue')
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in southern climates without significant care.
About This Grass
A dense, low-growing turf with a rich dark-green to blue-green color. It features smooth, upright-growing stems and forms a soft, carpet-like texture. Visible seed heads are panicle-type, pyramid-shaped, and usually appear in late spring if left unmowed.
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or flat; boat-shaped (keel-shaped) leaf tips; dark green color; folded vernation in the bud; short, membranous ligule; no auricles.
Root System
Relatively shallow compared to fescues, but develops an extensive network of rhizomes that allow for excellent sod formation, recovery from traffic, and thick thatch accumulation.
Growing Information
Origin Region
Native to Europe, North Asia, and Northern Africa; widely naturalized in North America across cool, humid regions.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod.
Sunlight & Water Needs
Full sun preferred (at least 6-8 hours); moderate to high water needs; poor shade tolerance; enters dormancy during hot, dry summer periods without irrigation.
Mowing & Maintenance
Ideal height of 2 to 3.5 inches; high maintenance; requires significant nitrogen (3-5 lbs N per 1000 sq ft annually); benefits from core aeration to manage thatch.
Special Characteristics
Excellent wear tolerance and self-healing ability due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; high aesthetic value for home lawns.
Ecological Information
Introduced in North America; provides cover for small birds and insects; excellent at stabilizing soil in temperate climates; often blended with perennial ryegrass or fine fescues.