Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, occasionally found as a weed in garden beds
Variety / Cultivar
Generic / Common (Likely an escaped turf variety)
Hardiness Zones
USDA Zones 3-7; excellent cold tolerance, poor heat tolerance above Zone 8.
About This Grass
A dark green, upright grass that grows in small clumps or thick sod. When unmowed, it produces fine panicle seed heads. In this garden bed setting, it appears as a thin, upright cluster next to broadleaf perennials.
Blade Characteristics
Blade width is medium (2-4mm) with a distinct boat-shaped tip; color is dark green to blue-green; vernation is folded in the bud; ligules are short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system with extensive rhizomes; known for high thatch tendency and excellent sod-forming ability.
Growing Information
Origin Region
Native to Europe, Northern Asia, and North Africa; naturalized throughout North America
Growth Habit
Rhizomatous (spreading underground), forming a dense mat or sod
Sunlight & Water Needs
Full sun to very light shade; prefers consistent moisture and has moderate drought tolerance (goes dormant during hot, dry periods).
Mowing & Maintenance
Ideal height 2.5-3.5 inches; requires regular fertilization (3-4 lbs nitrogen/1000 sq ft/year) and periodic dethatching; high maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; high salt sensitivity.
Ecological Information
Introduced species in North America; provides forage for livestock and nesting cover for small birds; can be invasive in native grasslands; often mixed with Fine Fescue for shade or Perennial Ryegrass for wear.