Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
General species type, highly variable cultivar selection including types like Midnight, Baron, and Bewitched known for rich dark green color and dense turf formation.
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7. Good cold tolerance, surviving harsh winters through dormancy, but less adapted to extreme humid heat found in the deep south unless heavily managed.
About This Grass
Forms a dense, high-quality turf with a fine to medium texture. Color ranges from medium to dark green, sometimes with a blue-green hue. Unmowed height can reach 18 to 24 inches, but it is typically maintained low as a lawn. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium in width (2-4mm), flat to folded with distinct parallel veins and parallel sides ending in characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, auricles are absent, and the collar is narrow and continuous.
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes. Tends to form moderate thatch under high management. Establishes slowly from seed, but spreads aggressively once mature to form a tough, wear-resistant sod.
Growing Information
Origin Region
Native to Europe, northern Asia, and parts of the mountains of North America; widely naturalized and cultivated across cool-temperate regions worldwide.
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf mat and sod.
Sunlight & Water Needs
Requires full sun for optimal performance (minimum 6-8 hours daily), though some modern cultivars show moderate shade tolerance. Moderate to high water needs; goes into summer dormancy under drought conditions if unwatered, but recovers well from crowns when moisture returns. Prefers well-drained, fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height ranges from 1.5 to 2.5 inches. Requires regular mowing during active spring and fall growth periods. High fertilization needs (2-4 lbs N per 1000 sq ft per year) for best color and density. Regular dethatching and core aeration are recommended due to sod-forming and thatch tendencies. Medium to High maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to aggressive rhizome spread. Moderate shade tolerance depending on cultivar. Good drought recovery via underground rhizomes. Prone to certain diseases like summer patch, dollar spot, and leaf spot under high stress.
Ecological Information
Widely introduced and naturalized across North America. Provides good soil stabilization and erosion control due to dense root and rhizome network. Often blended with perennial ryegrass and fine fescues in lawn seed mixes to improve establishment speed and disease resistance.