Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Pasture/Forage Grass
Variety / Cultivar
Common-type (represented by wide-ranging phenotypic expressions)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor performance in deep South/Humid subtropical regions.
About This Grass
A dark-green, cool-season turfgrass with a boat-shaped leaf tip and distinct open-panicle seed heads (though the image shows immature, contracted panicles during anther emergence). Typically reaches 12-24 inches when unmowed.
Blade Characteristics
Fine to medium width (2-4mm); flat or slightly folded; unique boat-shaped tip; dark green to blue-green color; vernation is folded in the bud; membranous ligule; no auricles; smooth collar.
Root System
Moderately shallow fibrous root system with extensive rhizomes; forms a tight, durable sod; high thatch-forming tendency; slow to moderate establishment from seed.
Growing Information
Origin Region
Native to Europe, North Asia, and Northern Africa; widely naturalized in North America and temperate climates globally
Growth Habit
Rhizomatous (spreading via underground stems), form dense sod over time
Sunlight & Water Needs
Full sun preferred (requires 6+ hours); moderate shade tolerance; high water needs; enters summer dormancy during severe drought and heat.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches; high maintenance; requires 2-4 lbs Nitrogen per 1000 sq ft annually; requires regular aeration to manage thatch.
Special Characteristics
Excellent wear recovery due to rhizomes; high turf quality and density; susceptible to dollar spot, leaf spot, and necrotic ring spot.
Ecological Information
Introduced in North America; provides forage for livestock and nesting cover for small birds; good soil stabilizer; an essential component of 'Northern' lawn mixes with Fescue and Ryegrass.