Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf, Pasture, Sports Turf
Variety / Cultivar
Common-type (Wild/Naturalized) or 'Midnight' type
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance (goes dormant in summer in transition zones).
About This Grass
A dense, sod-forming grass with a dark green color. It typically reaches 12-24 inches when unmowed. The flower heads are open, airy panicles, though the specific photo shows early-season inflorescence stalks with distinct purplish-green spikelets.
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or folded; distinctive boat-shaped (keeled) tip; dark green to blue-green; folded vernation; membranous ligule; no auricles.
Root System
Fibrous and rhizomatous; moderate depth; high thatch-forming tendency; slow to moderate establishment speed but excellent sod density.
Growing Information
Origin Region
Native to Europe, Asia, and North Africa; naturalized throughout North America
Growth Habit
Rhizomatous (spreading underground) and bunch-forming
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate to high water needs; poor shade tolerance; enters dormancy during severe drought.
Mowing & Maintenance
1.5 to 3.5 inches; high maintenance; 2-4 lbs Nitrogen per 1000 sq ft per year; requires periodic dethatching and aeration.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; high salt sensitivity.
Ecological Information
Introduced/Naturalized in US; provides forage for livestock and nesting cover for small birds; extremely effective for soil stabilization and erosion control.