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 Fairways
Variety / Cultivar
Standard Northern Blend / Common Type
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7, extending into zone 8 with irrigation. Excellent cold tolerance, surviving sub-zero winter temperatures through winter dormancy.
About This Grass
Forms a dense, high-quality turf with a fine to medium texture and rich dark green to blue-green color. Matures up to 12 to 24 inches if left unmowed, but usually maintained between 1.5 and 2.5 inches. Produces open, pyramidal panicle seed heads in late spring.
Blade Characteristics
Medium-narrow blades (2-4mm wide) with distinctive boat-shaped tips and parallel sides. Folded vernation in the bud shoot. Smooth texture with two prominent translucent lines running parallel to the midvein. Short membranous ligule with no auricles.
Root System
Moderately deep fibrous root system combined with aggressive underground rhizomes. High tendency to form thatch if heavily fertilized. Moderate to slow establishment speed from seed, but excellent long-term wear recovery.
Growing Information
Origin Region
Europe, Northern Asia, and mountainous regions of North America; cultivated globally in temperate climates
Growth Habit
Rhizomatous, spreading underground via extensive horizontal root runners to form a dense, uniform turf mat
Sunlight & Water Needs
Performs best in full sun requiring at least 6 to 8 hours of direct sunlight. Moderate to high watering needs; goes dormant during severe drought and greens up quickly with moisture. Prefers well-drained, fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches height. Requires frequent mowing during peak spring and fall growth periods. High fertilizer requirement (3-5 lbs N per 1000 sq ft annually). Requires periodic dethatching and core aeration. Maintenance level is high.
Special Characteristics
Exceptional wear and traffic tolerance due to aggressive rhizomatous spread and self-repairing nature. Moderate shade tolerance (prefers full sun). Good disease resistance depending on the cultivar, though susceptible to dollar spot and leaf spot under stress.
Ecological Information
Introduced species in North America widely naturalized across temperate zones. Excellent soil stabilization and erosion control due to dense root and rhizome network. Commonly mixed with Perennial Ryegrass and Tall Fescue in northern turf seed blends.