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 blend of elite turf cultivars such as 'Midnight' or 'Baron', known for dark green color and dense sod formation
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7. Has excellent cold tolerance and winter dormancy, but struggles with extreme summer heat unless irrigated.
About This Grass
Forms a dense, high-quality turf with a fine to medium texture and rich dark green to blue-green color. Mowed height is typically 2 to 3 inches, while unmowed growth can reach 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Blades are medium-width (2-4mm), flat to folded with distinct parallel veins and characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system with aggressive underground rhizomes. Forms a dense sod, has moderate thatch-forming tendencies, and exhibits medium-slow establishment speed from seed.
Growing Information
Origin Region
Europe, northern Asia, and mountainous regions of North America; widely cultivated throughout cool and transition zones globally
Growth Habit
Rhizomatous, spreading extensively 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 offer moderate shade tolerance. Requires regular moisture, entering summer dormancy during extended drought.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.5 inches. Requires medium-high maintenance including regular fertilization (3-4 lbs N per 1000 sq ft annually), periodic aeration, and dethatching.
Special Characteristics
Excellent wear tolerance and recovery capability due to rhizomes. Good cold hardiness, moderate traffic tolerance, and self-repairing nature make it popular for home lawns and athletic fields.
Ecological Information
Widely naturalized in North America. Provides good soil stabilization and erosion control, forms dense weed-resistant turf, and is frequently blended with Perennial Ryegrass and Fine Fescue.