Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass
Hardiness Zones
USDA Hardiness Zones 3-7; excellent cold tolerance, struggles in extreme southern heat unless heavily irrigated
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Midnight type (known for dark green color and dense growth)
About This Grass
Forms a dense, medium-fine textured turf with rich dark green to blue-green color; grows 1.5 to 2.5 feet tall if unmowed, but maintained at 2 to 3 inches; produces open, pyramidal panicle seed heads in late spring
Blade Characteristics
Medium-fine width (2-4mm), flat to V-shaped blades with characteristic boat-shaped tips and prominent parallel veins (tramline effect); folded in the bud (vernation); short membranous ligule and absent auricles
Root System
Moderately deep fibrous root system complemented by aggressive rhizomes; forms a very dense sod, moderate to high thatch tendency depending on management, moderate establishment speed
Growing Information
Origin Region
Europe and Northern Asia; widely cultivated across North America, especially the northern United States and Canada
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf and strong sod
Sunlight & Water Needs
Full sun preferred (minimum 6 hours direct sunlight), moderate to high water requirements during dry periods, good cold-induced winter dormancy with moderate-to-good drought dormancy recovery
Mowing & Maintenance
Mow at 2.0 to 3.0 inches regularly; requires medium to high maintenance including 2-4 lbs N per 1000 sq ft annually, regular irrigation, and periodic core aeration and dethatching
Special Characteristics
Good traffic and wear tolerance due to aggressive rhizomatous recovery, excellent cold hardiness, moderate shade tolerance compared to fine fescues, outstanding self-repairing capability, widely used for residential and sports turf
Ecological Information
Introduced species in North America; provides soil stabilization, erosion control, and moderate urban wildlife habitat; frequently blended with perennial ryegrass and fine or tall fescues