Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 pathway; classic northern turfgrass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common/Unknown cultivar (appears as a standard household lawn mix, possibly mixed with Fine Fescue)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in deep south; goes dormant in winter/extreme summer heat.
About This Grass
Medium-textured, dark-green turf grass known for its high density and soft feel. It grows 6-12 inches if unmowed, exhibiting a boat-shaped leaf tip and panicle-type seed heads.
Blade Characteristics
Blade width 2-4mm (medium); V-shaped or flat; distinctive boat-shaped (keeled) tip; dark green to blue-green color; vernation is folded in the bud; ligule is short and membranous; no auricles.
Root System
Moderately shallow fibrous root system with extensive rhizomes; tendency to form a dense thatch layer; slow establishment from seed compared to ryegrass.
Growing Information
Origin Region
Native to Europe, North Asia, and Morocco; well-adapted across Northern USA and Canada
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod
Sunlight & Water Needs
Prefers Full Sun (6+ hours); moderate shade tolerance; requires regular irrigation; goes dormant during severe drought to survive; prefers pH 6.0-7.0.
Mowing & Maintenance
Recommended 2.0-3.5 inches; high maintenance; requires 3-5 lbs N per 1000 sq ft annually; regular aeration and dethatching needed due to rhizome growth.
Special Characteristics
High wear tolerance and recovery due to rhizomes; excellent winter hardiness; susceptible to periodic leaf spot and necrotic ring spot; high aesthetic value.
Ecological Information
Introduced species in North America; provides soil stabilization; provides nesting material for urban birds; often blended with Perennial Ryegrass for traffic resistance.