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
Standard turf-type cultivar blend (e.g., 'Midnight' or 'Baronie')
Hardiness Zones
USDA Hardiness Zones 3 to 7, exhibits excellent cold tolerance, moderate heat tolerance, and struggles in extreme southern summer heat unless heavily irrigated.
About This Grass
Forms a dense, uniform, fine-to-medium textured turf with a rich green to blue-green color. Reaches heights of 18 to 24 inches if unmowed, but maintained at 1.5 to 2.5 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded with prominent parallel veins and a distinctive boat-shaped tip. Vernation is folded in the bud. Ligule is short and membranous, auricles are absent.
Root System
Moderately deep fibrous root system combined with aggressive underground rhizomes, forming a tough, dense sod. High tendency to develop thatch over time. Slow to establish from seed.
Growing Information
Origin Region
Europe and northern Asia; widely naturalized and cultivated across North America and cool-temperate regions worldwide
Growth Habit
Rhizomatous, producing a dense sod via underground stems
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for optimal growth, with moderate to high water needs. Good cold-induced winter dormancy, moderate drought dormancy, and prefers well-drained loamy soils with pH 6.0-7.0.
Mowing & Maintenance
Ideal mowing height ranges from 2.0 to 3.5 inches. Requires frequent mowing during peak spring/fall growth. High maintenance level needing regular fertilization (3-5 lbs N/1000 sq ft/year), periodic dethatching, and aeration.
Special Characteristics
Exceptional wear tolerance and self-repairing capability due to rhizomes. Good cold tolerance, moderate shade and salt tolerance. Susceptible to diseases like summer patch, dollar spot, and leaf spot.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome matrix. Commonly blended with perennial ryegrass and fine fescues for home lawns and athletic fields.