Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
General species type (common turf varieties include 'Midnight', 'Bewitched')
Hardiness Zones
USDA Hardiness Zones 3 to 7 (thrives in northern climates); excellent cold tolerance, moderate heat tolerance.
About This Grass
Forms a dense, high-quality turf with a medium to fine texture and rich green to blue-green color. Mows cleanly and establishes a thick carpet. Typical unmowed height reaches 18 to 24 inches with panicle seed heads, while maintained turf is kept between 1.5 to 3 inches.
Blade Characteristics
Medium-fine width (2-3mm), flat to V-shaped blades with characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous. Auricles are absent. Glossy underside with prominent parallel veins.
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes. Moderate establishment speed from seed, forms a very tough and dense sod that resists wear well once mature.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous with aggressive underground creeping stems, forming a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6 hours daily) for optimal growth; low shade tolerance. Moderate to high water needs; goes into summer dormancy (turning brown) during severe drought but recovers well with irrigation. Prefers well-drained, fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches. Medium to high maintenance level. Requires 2-4 lbs N per 1,000 sq ft annually. Regular watering, annual aeration, and occasional dethatching are recommended.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomes; good self-repair capability. Susceptible to certain diseases like dollar spot, melting-out, and summer patch under high humidity and stress. Excellent winter color retention in cooler regions compared to warm-season grasses.
Ecological Information
Introduced species in North America. Provides dense soil stabilization and effective runoff/erosion control. Commonly blended with Perennial Ryegrass and Fine Fescues to create durable lawn mixtures.