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 Fairway
Variety / Cultivar
Common or Elite type (e.g., 'Midnight' or 'Baron' styles indicated by density)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; goes dormant/brown in extreme cold or drought.
About This Grass
Medium-textured turf with a distinctive dark green to blue-green color; forms a lush, carpet-like mat that fills in bare spots via rhizomes; reaches 6-12 inches if unmowed; panicle-type seed heads.
Blade Characteristics
Boat-shaped (v-shaped) leaf tips, 2-4mm width, folded vernation, smooth leaf surfaces with a prominent midrib (twin lines), lack of auricles, and a short membranous ligule.
Root System
Produces a shallow to moderate fibrous root system with aggressive underground rhizomes; moderate thatch builder; slow to establish from seed but creates high-tensile sod.
Growing Information
Origin Region
Native to Europe, Northern Asia, and parts of Africa; widely adapted to temperate climates
Growth Habit
Rhizomatous (spreading via underground runners), forms a dense, uniform sod
Sunlight & Water Needs
Prefers Full Sun (6+ hours); moderate shade tolerance; requires regular irrigation (approx. 1 inch/week) to maintain green color during summer; enters dormancy under high heat and drought.
Mowing & Maintenance
Mowing height 2.0-3.5 inches; moderate to high maintenance; requires 2-4 lbs Nitrogen per 1000 sq ft annually; needs periodic dethatching and aeration due to rhizome growth.
Special Characteristics
Excellent wear recovery due to rhizomatous growth; high aesthetic value; susceptible to leaf spot, melt-out, and necrotic ring spot; slow germination (14-21 days).
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization via dense sod networking; significant forage value for livestock and nesting cover for small birds when unmowed.