Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
Common or various blended cultivars such as 'Midnight', 'Bewitched'
Hardiness Zones
USDA Hardiness Zones 3 to 7 (thrives in northern temperate climates, struggles in extreme southern heat unless heavily irrigated).
About This Grass
Forms a dense, high-quality, medium-fine textured turf with rich dark green to blue-green coloration. Reaches up to 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium-fine (2-3mm width), flat or folded with prominent parallel veins and distinctive boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous root system with moderate depth (6-12 inches). Tends to build up thatch over time if heavily fertilized. Establishes relatively slowly from seed compared to ryegrass.
Growing Information
Origin Region
Europe and northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for optimal growth, though some cultivars have moderate shade tolerance. Requires regular moisture (1 inch per week) and has moderate drought tolerance, entering summer dormancy during prolonged dry spells.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during active spring/fall growth. High fertilizer requirement (3-4 lbs N per 1000 sq ft annually). Moderate to high maintenance level.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizome recovery. Good cold hardiness. Moderate salt tolerance. Poor shade tolerance compared to fine fescues.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome network. Commonly blended with Perennial Ryegrass and Tall Fescue in northern turf mixes.