Kentucky Bluegrass
Poa pratensis · Cool-season (C3), Perennial
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Generic (contains characteristics of aggressive local types)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters winter dormancy; struggles in humid transition zones without irrigation.
About This Grass
A dense, low-growing turf with a rich dark-green color. It exhibits a medium-fine texture and a high density. When maintained, it forms an even carpet; when unmowed, it can reach 12-24 inches with open, panicle seed heads.
Blade Characteristics
Narrow to medium (2-4mm); V-shaped or flat; unique boat-shaped tip; dark green to bluish-green color; vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous roots supplemented by extensive rhizomes; tends to form thatch over time; slow establishment from seed but high wear recovery once established.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized in North America and temperate climates globally
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, uniform sod
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance varies by cultivar; high water needs during summer; goes dormant during severe drought or high heat; prefers well-drained, fertile soils with pH 6.0-7.0.
Mowing & Maintenance
Height: 2.0-3.5 inches; frequency: weekly during active growth; fertilization: 2-4 lbs N/1000 sq ft annually; high maintenance due to dethatching and aeration needs.
Special Characteristics
Excellent traffic tolerance and recovery due to rhizomes; highly susceptible to Summer Patch, Dollar Spot, and Rust; creates the highest quality aesthetic for home lawns.
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization; provides low-level cover for small insects; commonly mixed with Perennial Ryegrass or Fine Fescue for improved resilience.