Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common/Mixed Cultivar (e.g., Baron or Midnight types)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance, poor heat tolerance in the Deep South.
About This Grass
A dense, sod-forming grass that produces a lush, dark-green canopy. It reaches 6-12 inches if unmowed, producing tiny panicle-type seed heads. Maintains color well in cool autumn months.
Blade Characteristics
Fine to medium width (2-4mm), smooth and boat-shaped at the tip. Typically dark green to blue-green with a folded vernation, no auricles, and a short membranous ligule.
Root System
Relatively shallow but thick fibrous root system with extensive rhizomes. Forms heavy thatch and dense sod; moderate establishment speed from seed.
Growing Information
Origin Region
Europe, Northern Asia, and North Africa; now well-adapted to Northern US and Canada
Growth Habit
Rhizomatous (spreading via underground stems) with mat-forming tendencies
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) but tolerates partial shade. Requires regular watering; goes dormant (turns brown) during summer drought to survive.
Mowing & Maintenance
Ideal height 2.5 to 3.5 inches. High maintenance: requires regular fertilization (3-5 lbs N per 1000 sq ft) and annual aeration to manage thatch.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot and dollar spot; low salt tolerance; high aesthetic value for home lawns.
Ecological Information
Introduced and naturalized in North America. Provides soil stabilization and filtration; can be aggressive in native meadows. Often mixed with Perennial Ryegrass or Fine Fescue for diversity.