Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
'Midnight' or similar dark-green elite cultivars
Hardiness Zones
USDA Hardiness Zones 3-7, highly cold tolerant, goes into summer dormancy under extreme heat.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and rich dark-to-medium green color. Can grow up to 18-24 inches if left unmowed, but typically maintained at 1.5 to 2.5 inches.
Blade Characteristics
Blades are medium in width (2-4mm), flat to folded with prominent parallel veins and a distinctive boat-shaped tip. Vernation is folded in the bud with a short membranous ligule and absent auricles.
Root System
Moderately deep fibrous root system combined with aggressive underground rhizomes, forming a strong, dense sod that resists wear but can develop moderate thatch over time.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide.
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) with moderate to high water needs; good cold drought dormancy but fair summer heat stress vulnerability in transition zones.
Mowing & Maintenance
Ideal mowing height between 1.5 and 2.5 inches. Requires regular fertilization (3-4 lbs N per 1000 sq ft per year), periodic dethatching, and high maintenance level.
Special Characteristics
Excellent wear tolerance and self-repairing capability due to rhizomes, good cold tolerance, poor shade tolerance relative to other cool-season grasses.
Ecological Information
Introduced species in North America, provides standard turf ecosystem benefits, frequently blended with Perennial Ryegrass and Tall Fescue.