Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf
Hardiness Zones
Thrives in USDA Hardiness Zones 3 to 7. Excellent cold tolerance (survives harsh winters under dormancy), but struggles with extreme summer heat and humidity in the deep southern US transition zones.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Midnight (known for dark blue-green color, dense growth, and good disease resistance)
About This Grass
Forms a dense, high-quality turf with medium-fine texture and a rich dark green to blue-green color. Maintained height is typically 1.5 to 2.5 inches, while unmowed growth can reach 18 to 24 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (3-4mm), flat to folded shape with distinctive boat-shaped tips. Dark green to blue-green color. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent. The blade features prominent parallel veins and a smooth texture.
Root System
Moderately deep fibrous root system combined with vigorous rhizomes. Tends to build up moderate thatch over time. Establishes slowly from seed, but spreads well once mature to repair damaged areas and form a tough sod.
Growing Information
Origin Region
Europe and northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf sod
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily) for optimal performance; moderate shade tolerance. High watering needs to maintain active growth during dry spells, with moderate drought dormancy. Prefers well-drained fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height ranges from 2.0 to 3.0 inches. Requires frequent mowing during peak spring/fall growth. High fertilizer requirement (3-4 lbs N per 1000 sq ft annually). Needs periodic dethatching, core aeration, and high maintenance overall.
Special Characteristics
Good wear tolerance and self-healing via rhizomes. Moderate shade tolerance, low salt tolerance, and susceptible to certain diseases like dollar spot and summer patch under stress. Excellent for home lawns and sports fields.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense root and rhizome network. Often blended with perennial ryegrass and fine fescues for balanced lawn establishment and resilience.