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 or mixed turf type (e.g., 'Midnight', 'Baron')
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7. Excellent cold tolerance, goes semi-dormant or brown during extreme summer heat or severe drought.
About This Grass
Forms a dense, fine-to-medium textured carpet of rich green to blue-green color. Reaches 18-24 inches if left unmowed but maintained at 1.5-2.5 inches. Produces open, pyramid-shaped panicle seed heads at maturity.
Blade Characteristics
Medium-fine blades (2-4mm wide), V-shaped to flat with distinct parallel veins and characteristic boat-shaped tips. Folded in the bud (vernation). Short, membranous ligule and no auricles.
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes. Forms a very tough, dense sod. Moderate establishment speed, slow to germinate from seed.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense, uniform turf mat and sod via underground stems
Sunlight & Water Needs
Requires full sun (minimum 6 hours direct sunlight) for optimal performance, though some cultivars offer moderate shade tolerance. High water needs during hot, dry periods to prevent summer dormancy; moderate drought tolerance by going dormant.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires regular mowing, moderate to high fertilization (3-5 lbs N per 1000 sq ft annually), occasional dethatching due to dense sod, and core aeration. Maintenance level is Medium-High.
Special Characteristics
Excellent wear tolerance and traffic recovery due to aggressive rhizomes. Good cold hardiness, moderate disease susceptibility (e.g., dollar spot, leaf spot), poor shade tolerance relative to fescues.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome matrix. Frequently blended with Perennial Ryegrass and Fine Fescues for enhanced turf resilience.