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 mixed turf cultivars (e.g., 'Midnight', 'Baron')
Hardiness Zones
USDA Zones 3-7; excellent cold tolerance (survives harsh winters); can struggle in extreme southern heat unless irrigated; widely used in the northern US and cooler transition zones
About This Grass
Forms a dense, fine-to-medium textured turf with an attractive dark to medium blue-green color; grows 1.5 to 2.5 feet tall if left unmowed; features pyramid-shaped panicle seed heads at maturity
Blade Characteristics
Medium-fine blades (2-4mm wide) with distinctive boat-shaped tips, folded vernation in the bud shoot, parallel veins, prominent midvein giving a tramline appearance, membranous ligule, and absent auricles
Root System
Moderately deep fibrous root system combined with aggressive rhizomes; establishes slowly from seed but forms a tough, tight sod with moderate to high thatch-forming tendencies
Growing Information
Origin Region
Europe, northern Asia, and the mountains of northern North America; widely cultivated in northern and transitional climates globally
Growth Habit
Rhizomatous, spreading underground via slender horizontal stems to form a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6 hours of direct sunlight) for optimal performance; moderate to high water needs; enters summer dormancy during drought but recovers well when irrigated; prefers well-drained, fertile soils with a pH of 6.0 to 7.0
Mowing & Maintenance
Mow at 2.0 to 3.0 inches height; requires regular mowing during peak growth seasons; fertilization needs are high (3-5 lbs N per 1000 sq ft annually); regular aeration and dethatching are recommended; maintenance level is high
Special Characteristics
Exceptional wear and traffic tolerance due to aggressive rhizomatous recovery; good winter color retention in milder cool regions; prone to certain diseases like dollar spot and leaf spot; excellent self-repairing turfgrass
Ecological Information
Introduced species in North America; provides ground cover and erosion control; low wildlife food value compared to native prairie grasses; frequently blended with Perennial Ryegrass and Fine Fescues to create resilient lawn mixes