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 (such as 'Midnight' or 'Boutique')
Hardiness Zones
USDA Hardiness Zones 3-7. Excellent cold tolerance, goes dormant in extreme winter freezes, and can struggle with severe summer heat in the southern transition zones.
About This Grass
Forms a lush, dense, dark green to blue-green turf with a fine to medium texture. Grows 1.5 to 2.5 feet tall if unmowed, but usually maintained at 2 to 3 inches. Produces panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (3-4mm), flat to folded shape with distinctive boat-shaped tips and prominent parallel veins. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous root system extending moderately deep (6-12 inches). Moderate to high thatch-forming tendency. Slow to establish from seed, but forms an extremely tough, dense sod once mature.
Growing Information
Origin Region
Europe, northern Asia, and parts of the mountains of the western US. Thrives in northern US and Canada.
Growth Habit
Aggressively rhizomatous, forming a dense, uniform sod with underground runners.
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily), moderate to high watering needs, and goes into summer dormancy under severe drought unless irrigated. Prefers well-drained, fertile loams with pH 6.0-7.0.
Mowing & Maintenance
Maintain at 2.0 to 3.5 inches. Mowing frequency is high during spring growth peaks. Requires 3-4 lbs of nitrogen per 1000 sq ft annually. High maintenance level with regular aeration and dethatching.
Special Characteristics
Exceptional wear tolerance and self-repairing capability via rhizomes. Moderate shade tolerance compared to fine fescues. Good winter color retention in milder northern zones.
Ecological Information
Introduced to North America by European settlers. Provides standard lawn ecosystem benefits, highly valued for erosion control and dust suppression. Frequently mixed with perennial ryegrass and fine fescues.