Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
General species (commonly cultivars like 'Midnight' or 'Baron')
Hardiness Zones
USDA Hardiness Zones 3 to 7, exhibits excellent cold tolerance, goes semi-dormant or brown during severe summer heat or prolonged drought.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and rich dark green to blue-green color. Reaches 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Develops open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (3-4mm), flat to folded shape with characteristic boat-shaped tips. Vernation is folded in the bud. Color ranges from dark green to blue-green. Prominent parallel veins with a distinct light-colored midrib and tramlines. Ligule is short and membranous, auricles are absent.
Root System
Moderate rooting depth with extensive fibrous roots and strong rhizomes. Forms a dense, tough sod that creates a high tendency for thatch if over-fertilized. Moderate establishment speed from seed.
Growing Information
Origin Region
Europe and Northern Asia; widely cultivated and naturalized across North America, especially in the northern US and Canada
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily) for best performance, with moderate to high water needs. Moderate-to-good drought tolerance through summer dormancy, preferring well-drained loamy soils with pH 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires medium-high maintenance including regular fertilization (3-4 lbs N per 1000 sq ft annually), frequent mowing, periodic dethatching, and core aeration.
Special Characteristics
Excellent wear tolerance and self-repairing capability via rhizomes. Good cold tolerance, moderate shade tolerance compared to fine fescues, and forms a dense sod ideal for home lawns and sports fields.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control through its dense root and rhizome network. Commonly blended with Perennial Ryegrass and Fine Fescues in northern turf seed mixes.