Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common blend, often including elite cultivars like 'Midnight' or 'Compact', known for dark green color and dense sod.
Hardiness Zones
USDA Hardiness Zones 3 to 7, thriving in northern and transition zones. Excellent cold tolerance, goes dormant in extreme winter cold and summer heat.
About This Grass
Forms a dense, medium-textured turf with an attractive rich green to dark blue-green color. When unmaintained, it can grow up to 18-24 inches tall with open panicle seed heads, but is typically maintained at 2 to 3.5 inches.
Blade Characteristics
Medium width (2-4mm), folded in the bud (vernation), with distinct parallel veins and characteristic boat-shaped tips. Ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system combined with vigorous rhizomes. Establishes relatively slowly from seed, but forms a very tough, dense sod once established with moderate thatch-forming tendencies.
Growing Information
Origin Region
Europe, northern Asia, and the mountains of northern North America; widely cultivated across cool and temperate regions globally.
Growth Habit
Aggressively rhizomatous, spreading via underground stems to form a dense, uniform turf mat.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for best performance, though some cultivars have moderate shade tolerance. High watering needs during dry spells to stay green; enters dormancy during severe drought.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches. Requires regular mowing, moderate to high fertilization (2-4 lbs N per 1000 sq ft annually), periodic aeration, and dethatching. High maintenance level.
Special Characteristics
Exhibits excellent wear tolerance and remarkable self-repair capabilities via rhizomes. Good cold tolerance, moderate drought recovery through underground rhizomes, and forms a thick carpet that naturally crowds out most weeds.
Ecological Information
Introduced to North America by European settlers. Widely used for home lawns, athletic fields, and golf course fairways. Provides standard turfgrass ecological services like soil stabilization and temperature moderation, and is frequently blended with Perennial Ryegrass and Fine Fescues.