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 (Fairways/Tees)
Variety / Cultivar
Likely a blend such as 'Midnight', 'Mazama', or generic 'common' Kentucky Bluegrass due to high density and deep green color.
Hardiness Zones
USDA Hardiness Zones 2 through 7; thrives in cool, humid climates. Excellent cold tolerance but struggles in extreme heat and humidity found in zones 8-10.
About This Grass
A medium-textured, high-density turf grass with a distinct dark green to blue-green color. It features a lush, carpet-like appearance and maintains a consistent look when mowed frequently. Unmowed, it can reach 12-24 inches with panicle-shaped seed heads.
Blade Characteristics
Blade width is medium (2-4mm), featuring a signature V-shape and boat-shaped (cupped) tips. Vernation is folded in the bud. The upper leaf surface is smooth with a prominent mid-vein (keel). Ligule is short and membranous; auricles are absent.
Root System
Features a dense network of shallow to moderate fibrous roots and aggressive underground rhizomes. This promotes excellent sod strength and recovery from wear, though it makes the grass prone to thatch buildup.
Growing Information
Origin Region
Native to Europe, Asia, and North Africa; naturalized across North America, particularly in the northern United States and Canada.
Growth Habit
Rhizomatous (spreading via underground stems), forming a thick, dense, sod-forming mat that fills in bare spots easily.
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) but has moderate shade tolerance. Requires consistent moisture with roughly 1 inch of water per week; displays moderate drought tolerance but will enter summer dormancy (turn brown) to protect itself during extended dry spells.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches. High maintenance level requiring 2-4 lbs of Nitrogen per 1000 sq ft annually. Needs regular dethatching and aeration to manage the rhizomatous mat.
Special Characteristics
Exceptional wear tolerance and self-repairing capabilities due to rhizomes. Susceptible to leaf spot, melting-out, and necrotic ring spot. Excellent winter color retention compared to warm-season grasses.
Ecological Information
Introduced status in North America; provides basic cover for small wildlife and stabilization against erosion. Frequently blended with Tall Fescue or Perennial Ryegrass to increase disease resistance and diversity in residential lawns.