Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common or various blended cultivars such as 'Midnight'
Hardiness Zones
USDA Hardiness Zones 3 to 7, excellent cold tolerance, struggles in extreme summer heat unless irrigated, suitable for northern regions and upper transition zones.
About This Grass
Forms a dense, medium-textured turf with an upright growth habit. Bright to dark green color with high density, capable of self-repairing via underground rhizomes.
Blade Characteristics
Medium-fine width (2-3mm), flat to folded shape, distinctive boat-shaped tips, vernation folded in the bud, prominent parallel veins with a light-colored midrib.
Root System
Fibrous and rhizomatous root system with moderate depth, moderate to high thatch tendency, medium establishment speed from seed, excellent wear recovery due to spreading rhizomes.
Growing Information
Origin Region
Europe and Northern Asia, widely naturalized and cultivated across North America in cool-temperate climates
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high watering needs for optimal appearance, good cold-induced winter dormancy drought tolerance, prefers well-drained loamy soils with pH 6.0-7.0.
Mowing & Maintenance
Ideal mowing height 2.0 to 3.5 inches, frequent mowing during peak spring/fall growth, high maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft annually) and occasional dethatching/aeration.
Special Characteristics
High wear tolerance and excellent self-repair capability via rhizomes, moderate disease susceptibility (e.g., dollar spot, leaf spot), poor shade tolerance compared to fescues, excellent erosion control.
Ecological Information
Introduced species in North America, provides standard turf ecosystem benefits, helps prevent soil erosion, frequently blended with perennial ryegrass and fine fescues.