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
Common or various blended cultivars like 'Midnight' or 'Baron'
Hardiness Zones
USDA Hardiness Zones 3 to 7, thriving in northern and transition zones. Excellent cold tolerance, surviving sub-zero winter temperatures, though it goes dormant in extreme summer heat.
About This Grass
Forms a dense, high-quality, medium-fine textured turf with a rich green to blue-green color. Mowed height typically maintained between 1.5 and 2.5 inches, while unmowed growth can reach 18 to 24 inches with pyramidal panicle seed heads.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded shape with distinctive boat-shaped tips. Vernation is folded in the bud. Color ranges from medium green to dark blue-green. Features prominent parallel veins and a short, membranous ligule with absent auricles.
Root System
Moderately deep fibrous root system with extensive spreading rhizomes. Moderate to slow establishment speed from seed, but forms a very dense sod that offers excellent wear recovery and moderate drought tolerance through dormancy.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense sod and mat via underground spreading stems
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for optimal growth, with moderate to high water needs. Has good cold tolerance and enters summer dormancy under severe drought conditions. Prefers well-drained fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during peak spring/fall growth. High maintenance level needing 3-4 lbs of nitrogen per 1000 sq ft annually, along with regular aeration and occasional dethatching due to dense thatch buildup.
Special Characteristics
Exceptional wear tolerance and self-repairing capability via rhizomes. Good disease resistance when properly managed, moderate shade tolerance compared to fescues, and excellent erosion control due to dense root and rhizome matrix.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control, filters runoff water, and creates low-level wildlife habitat. Frequently mixed with perennial ryegrass and fine fescues for lawns.