Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Kentucky Bluegrass (Common or improved turf-type)
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance, poor heat tolerance in the Deep South.
About This Grass
A dark green, dense turfgrass with a soft texture. It forms a lush, uniform carpet and is prized for its aesthetic appeal. Managed turf reaches 2-4 inches, while unmowed seed heads can reach 12-24 inches with open, airy panicles.
Blade Characteristics
Fine to medium width (2-4mm), smooth and flat or slightly V-shaped. The most identifying feature is the boat-shaped (keeled) leaf tip and two prominent 'track' lines down the center of the leaf. Vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Fibrous and dense with extensive rhizomes. The rhizomatous system allows for excellent sod formation and self-repair capabilities, though the majority of the root mass is relatively shallow (top 6-10 inches).
Growing Information
Origin Region
Europe, North Asia, and Northern Africa; widely adapted to temperate climates globally
Growth Habit
Rhizomatous (spreading underground), forming a dense, sod-forming mat
Sunlight & Water Needs
Prefers Full Sun (6+ hours) but can tolerate light shade. Requires moderate to high water; enters summer dormancy during extended drought to survive. Ideal pH 6.0-7.0.
Mowing & Maintenance
Ideal height: 2.5-3.5 inches. Requires frequent mowing during peak spring/fall growth. Maintenance level is High, requiring 3-5 lbs of nitrogen per 1000 sq ft per year.
Special Characteristics
Outstanding wear recovery due to rhizomes, high aesthetic value, excellent winter hardiness, but susceptible to Leaf Spot, Dollar Spot, and Summer Patch in high humidity.
Ecological Information
Introduced species in North America; provides cover for small mammals; excellent for soil erosion control due to dense sod; often mixed with Fine Fescue or Perennial Ryegrass for biodiversity and resilience.