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 mixed turf cultivars (e.g., 'Midnight', 'Bewitched')
Hardiness Zones
USDA Hardiness Zones 3-7, excellent cold tolerance, moderate heat tolerance, goes dormant in extreme heat.
About This Grass
Forms a dense, fine-to-medium textured lawn with a rich, dark to medium green color. Reaches up to 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Features open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded shape with distinctive boat-shaped tips. Vernation is folded in the bud. Prominent parallel veins with two clear translucent lines on either side of the midrib.
Root System
Moderate depth (4-6 inches primarily, though can go deeper), fibrous with aggressive rhizomes. High thatch tendency under high fertility, moderate establishment speed.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via robust underground stems to form a dense, uniform turf mat
Sunlight & Water Needs
Full sun preferred (minimum 4-6 hours direct sunlight), moderate to high water requirements for optimal appearance, enters summer dormancy during severe drought.
Mowing & Maintenance
Ideal mowing height 2.0 to 3.0 inches. Medium to high maintenance level, requiring regular fertilization (3-4 lbs N per 1000 sq ft per year), periodic dethatching, and aeration.
Special Characteristics
High wear tolerance and excellent self-repairing capability due to rhizomes. Moderate shade tolerance, good disease recovery.
Ecological Information
Introduced species in North America, provides excellent erosion control, forms dense turf that filters runoff, often blended with Perennial Ryegrass and Tall Fescue.