Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass and Sports Turf
Hardiness Zones
USDA Hardiness Zones 3 through 7, with good cold tolerance down to -30°F or lower. Heat tolerance is moderate, often going semi-dormant in prolonged summer heat waves.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Common blend (such as 'Midnight' or 'Baron')
About This Grass
Forms a dense, medium-textured turf with an attractive medium to dark green or blue-green color. Maintained height is typically 1.5 to 2.5 inches, while unmowed growth can reach 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Medium width (2-4mm), flat to folded shape with distinctive boat-shaped tips and prominent parallel veins. Vernation is folded in the bud. Ligule is short and membranous, and auricles are absent.
Root System
Moderate depth fibrous root system with extensive underground rhizomes. Tends to form moderate thatch over time. Establishment from seed is slow, but rhizomatous spread allows rapid self-repair after damage.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide, performing best in northern climates.
Growth Habit
Rhizomatous, spreading underground via aggressive creeping roots to form a dense, uniform sod and dense mat.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for optimal growth, though some cultivars offer moderate shade tolerance. High water needs during dry spells to prevent summer dormancy; moderate drought tolerance by going dormant during extreme dry periods.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during peak spring/fall growth. High fertilizer requirement (3-5 lbs N per 1000 sq ft per year). Regular aeration and dethatching are recommended. Medium-high maintenance level.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomes and self-repairing nature. Moderate disease susceptibility (e.g., dollar spot, summer patch). Good winter color retention in milder cool-season zones.
Ecological Information
Introduced species in North America. Provides good soil stabilization, erosion control, and moderate wildlife habitat value. Frequently blended with Perennial Ryegrass and Tall Fescue in turf seed mixes.