Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Hardiness Zones
USDA Hardiness Zones 3-7, highly cold tolerant. Can struggle in extreme summer heat unless irrigated, placing it at the cooler edge of the transition zone.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
'Midnight' or similar dark green elite cultivar
About This Grass
Forms a dense, high-quality turf with a rich, dark blue-green color. Reaches heights of 18-24 inches if unmowed, but maintained as a lawn at 2-3 inches. Features fine to medium texture and produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium-width (2-4mm), flat to folded in the bud with distinctive boat-shaped tips and parallel sides. Color is a rich dark green to blue-green with prominent parallel veins. Features a short membranous ligule and lacks auricles.
Root System
Moderately deep fibrous root system combined with an aggressive network of underground rhizomes. Forms a very dense sod that provides excellent self-repairing wear recovery, though it has a moderate to high thatch-forming tendency and slow initial 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 extensively via underground stems to form a dense, uniform turf
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours of direct sunlight) for optimal growth, though some cultivars offer moderate shade tolerance. High water needs to maintain green color during summer; goes into summer dormancy under drought stress. Prefers well-drained, fertile soils with a pH of 6.0-7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during peak spring and fall growth. High maintenance level, needing 3-5 lbs N per 1000 sq ft per year, regular irrigation, and periodic dethatching/aeration.
Special Characteristics
Excellent traffic and wear recovery due to rhizomatous spreading. Good cold hardiness and winter color retention in milder winters. Moderate to high disease susceptibility (e.g., leaf spot, dollar spot, summer patch). Forms dense weed-resistant turf when properly managed.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control due to dense sod and rhizomes. Frequently blended with Perennial Ryegrass and Tall Fescue in commercial seed mixes to enhance turf recovery and pest resistance.