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 through 7. Excellent cold tolerance, surviving freezing winters underground via rhizomes, but struggles in extreme southern heat without irrigation.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
Midnight type (noted for dark green color and dense growth habit)
About This Grass
A classic dense turfgrass forming a lush, carpet-like lawn. Maintains a height of 1.5 to 2.5 inches when maintained, though can grow up to 18-24 inches if unmowed. Color is a rich dark blue-green to medium green, showing good cold-weather retention. Texture is medium-fine, creating a high-density, high-quality appearance at maturity.
Blade Characteristics
Blades are medium width (2-4mm), flat to folded with prominent parallel veins and a distinctive boat-shaped tip. Vernation is folded in the bud. The ligule is short and membranous, and auricles are absent.
Root System
Moderate to deep fibrous root system combined with extensive underground rhizomes. Moderate establishment speed from seed, but ultimately forms an extremely tough, dense sod with a tendency to build up thatch if over-fertilized.
Growing Information
Origin Region
Europe and northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide, performing best in northern temperate climates.
Growth Habit
Rhizomatous with aggressive underground spreading via rhizomes, forming a dense, uniform turf mat.
Sunlight & Water Needs
Requires full sun to partial sun (minimum 4-6 hours of direct sunlight). Moderate to high watering needs; goes into summer dormancy (turning brown) under drought conditions but recovers well when moisture returns. Prefers well-drained loamy soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Mowing frequency is high during active spring and fall growth periods. Requires a medium-high maintenance level, including 2 to 4 lbs of nitrogen per 1,000 sq ft annually, regular aeration, and occasional dethatching.
Special Characteristics
Exceptional wear tolerance and self-repairing capability due to spreading rhizomes. Moderate shade tolerance (better in mixed stands). Good drought recovery through underground survival mechanisms. Excellent erosion control and weed-crowding ability.
Ecological Information
Introduced to North America by European settlers. Provides standard lawn ecosystem services such as soil stabilization and carbon sequestration. Often blended with Perennial Ryegrass and Fine Fescues to improve disease resistance and adaptability.