Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Generic / Unspecified Kentucky Bluegrass (shares features of Common or Midnight types)
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor heat tolerance; goes dormant and turns brown during winter in northern climates.
About This Grass
A dense, low-growing turfgrass with a soft texture. It displays a deep emerald to blue-green color. Seed heads are open, airy panicles (pyramidal shape) roughly 2-8 inches tall if left unmowed.
Blade Characteristics
Fine to medium width (2-4mm); flat or slightly V-shaped; distinctive boat-shaped (keeled) tip; dark green to blue-green color; vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Moderately shallow fibrous root system with extensive horizontal rhizomes; forms thatch easily; takes longer to establish from seed compared to ryegrass but forms a self-repairing dense sod.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; widely adapted to temperate North America.
Growth Habit
Rhizomatous (spreading underground) with limited bunch-type growth; forms a dense, uniform sod over time.
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance; requires consistent moisture (~1 inch per week); low drought tolerance (goes dormant in high heat/drought); prefers well-drained soil pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; high maintenance; requires 2-4 lbs Nitrogen per 1000 sq ft annually; vertical mowing/dethatching needed periodically to manage rhizome buildup.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; high visual quality; susceptible to necrotic ring spot and summer patch; low salt tolerance; high ability to crowd out weeds when dense.
Ecological Information
Introduced/Naturalized (non-native to US); low wildlife food value but provides cover; excellent soil stabilizer for erosion control; commonly blended with Perennial Ryegrass or Fine Fescue for resilient turf.