Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Fairways
Variety / Cultivar
Common or Elite Kentucky Bluegrass (e.g., 'Midnight', 'Mazama', or 'After Midnight')
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor heat tolerance (enters dormancy in high heat); common in northern climates and the cooler parts of the transition zone.
About This Grass
A dense, high-quality turf with a medium-to-fine texture and a distinct rich emerald to dark blue-green color. It grows 18-36 inches if unmowed, producing an open, pyramidal panicle seed head. It is known for its ability to enter summer dormancy during drought.
Blade Characteristics
Fine to medium width (2-4mm); flat or slightly V-shaped; specifically features a boat-shaped ('canoe-shaped') tip; color is typically dark green; vernation is folded in the bud; ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system with extensive rhizomes; has a high thatch-forming tendency; establishment is slow from seed (2-3 weeks for germination) but forms a very durable sod.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; widely adapted to temperate climates globally.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, uniform, and self-repairing sod.
Sunlight & Water Needs
Full Sun preferred (6-8 hours); moderate shade tolerance; requires regular watering (1 inch per week) and has moderate drought tolerance through dormancy; prefers well-drained soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.0-3.5 inches; high maintenance; requires frequent mowing; fertilization 3-5 lbs Nitrogen per 1000 sq ft per year; requires periodic dethatching and aeration.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot, dollar spot, and summer patch; good salt tolerance; iconic for aesthetic beauty in home lawns.
Ecological Information
Introduced and naturalized in North America; provides forage for livestock and wildlife; stabilizes soil efficiently via rhizomes; often mixed with Perennial Ryegrass or Fine Fescue for improved shade and disease resistance.