Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common/Mixed Cultivar (characteristic of high-density turf blends)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; enters winter dormancy in freezing temperatures.
About This Grass
A dense, low-growing turf grass with a lush, dark green to blue-green color. It maintains a soft texture and uniform appearance when mowed regularly. It develops a thick sod through vigorous rhizome growth.
Blade Characteristics
Fine to medium width (2-4mm), smooth and flat or slightly folded. Key identifying feature: boat-shaped (keeled) leaf tips. Vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Relatively shallow fibrous root system combined with strong underground rhizomes. High thatch-forming tendency; moderate establishment speed from seed; excellent sod-forming capability for wear recovery.
Growing Information
Origin Region
Europe, Northern Asia, and North Africa; naturalized extensively in North America and temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, durable sod mat
Sunlight & Water Needs
Full Sun preferred (6+ hours); moderate shade tolerance; requires regular watering (1 inch per week). Best in well-drained, fertile soils with pH 6.0-7.5. Goes dormant during extreme drought.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; weekly mowing; high nitrogen requirement (2-4 lbs N per 1000 sq ft/year); requires periodic aeration and dethatching; maintenance level is moderate to high.
Special Characteristics
Excellent wear tolerance and self-repairing ability due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; high aesthetic value for residential lawns and sports fields.
Ecological Information
Introduced species in North America; provides soil stabilization and carbon sequestration; seeds provide food for songbirds and small mammals; often blended with Perennial Ryegrass or Fine Fescue for diverse turf biology.