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 Grass
Variety / Cultivar
Common or 'Midnight' type (Generic Turf-type Bluegrass)
Hardiness Zones
USDA Hardiness Zones 2 through 7. Excellent cold tolerance. Enters dormancy (turns brown) during extreme winter cold or summer heat/drought.
About This Grass
A medium-textured, deep green to blue-green grass that forms a high-density turf. It has an erect growth habit and becomes dormant during high heat or severe drought. Seed heads are open, spreading panicles (pyramid-shaped).
Blade Characteristics
Blade width is medium (2-4mm). The most distinctive feature is the boat-shaped (V-shaped) leaf tip and a prominent midrib with two translucent lines ('twin tracks'). Vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Relatively shallow to moderate fibrous root system supported by vigorous rhizomes. Low thatch-forming tendency if managed properly. Moderate establishment speed but excellent ability to recover from wear via rhizomatous growth.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Algeria and Morocco; highly adapted to northern United States and Canada.
Growth Habit
Rhizomatous (spreading via underground runners), forms a dense, tight sod which fills in bare spots automatically.
Sunlight & Water Needs
Prefers Full Sun (6-8 hours); moderate shade tolerance. High water needs; requires regular irrigation to stay green during summer. Prefers well-drained fertile soil with a pH of 6.0 to 7.5.
Mowing & Maintenance
Recommended height: 2.0 to 3.5 inches. High maintenance level; requires 2-4 lbs of Nitrogen per 1000 sq ft annually. Regular aeration recommended to manage sod density.
Special Characteristics
Exceptional cold hardiness, excellent self-repairing ability through rhizomes, high foot-traffic tolerance, and a beautiful uniform appearance. Susceptible to leaf spot, melting-out, and summer patch in high humidity.
Ecological Information
Introduced and naturalized in North America. Provides erosion control via dense sod. Offers nesting cover for small birds and is a food source for various moth larvae (sod webworms) and pollinators when flowering.