Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely a common lawn-type blend, potentially containing varieties like 'Midnight' or 'Kenblue'
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance, often going dormant (turning straw-colored) in high summer heat as seen in the photo.
About This Grass
A dense, sod-forming grass with a distinct dark blue-green color. It reaches 6-12 inches if unmowed, featuring a fine to medium texture and an open, pyramidal panicle seed head at maturity. The lawn in the image shows characteristic summer dormancy/browning under heat stress.
Blade Characteristics
2-4mm width, narrow and linear; unique boat-shaped tip (rounded/v-shaped); dark green to blue-green color; vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Moderate depth (mostly in top 6 inches) but dense and fibrous; strong rhizome production creates heavy thatch; slow to establish from seed but recovers well from wear due to rhizomes.
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco and Algeria; widely adapted to temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, uniform sod
Sunlight & Water Needs
Full sun preferred (6+ hours); high water requirement during summer; moderate to low drought tolerance; prefers well-drained soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; requires weekly mowing in spring/fall; 2-4 lbs Nitrogen per 1000 sq ft annually; requires regular dethatching and aeration; high maintenance level.
Special Characteristics
Excellent wear tolerance and recovery; good disease resistance in modern cultivars; poor shade tolerance; high ability to crowd out weeds once established via thick sod.
Ecological Information
Introduced in North America; provides soil stabilization and carbon sequestration; seeds provide food for songbirds and small mammals; often used in mixtures with Tall Fescue or Perennial Ryegrass.