Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass; currently behaving as a mixed residential lawn with high weed pressure
Variety / Cultivar
Common or Lawn-grade Kentucky Bluegrass (identifiable by boat-shaped tips and mixed lawn setting)
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; goes dormant and turns tan/brown in extreme cold or extreme heat/drought.
About This Grass
A medium-textured, cool-season grass that produces a lush, dark green carpet. In this image, it is seen intermixed with broadleaf weeds (Glechoma hederacea and Taraxacum), showing its ability to maintain growth in high-competition environments.
Blade Characteristics
Narrow to medium (2-4mm), V-shaped or flat, distinctive boat-shaped tip, dark green to blue-green color. Vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous; moderate depth (6-12 inches); high thatch-forming tendency; slow to moderate establishment speed but excellent recuperative potential due to rhizomes.
Growing Information
Origin Region
Europe, North Asia, and Northern Africa; naturalized throughout North America
Growth Habit
Rhizomatous (spreading underground), forming a thick, dense sod over time
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance; requires regular moisture (1 inch per week) and has moderate drought tolerance (enters dormancy during extreme heat/dry spells).
Mowing & Maintenance
Ideal height 2.5-3.5 inches; high maintenance; requires 2-4 lbs Nitrogen per 1000 sq ft annually; requires periodic core aeration and dethatching.
Special Characteristics
Excellent wear tolerance and recovery; high aesthetic value; highly susceptible to broadleaf weed encroachment if not maintained (as seen with Creeping Charlie and Dandelions in the image).
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization and carbon sequestration; often used in blends with Perennial Ryegrass or Fine Fescue for ecological diversity.