Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf
Variety / Cultivar
Standard turf blends, cultivars like 'Midnight' or 'Baron'
Hardiness Zones
USDA Hardiness Zones 3 to 7, excellent cold tolerance, struggles in extreme summer heat unless irrigated.
About This Grass
Forms a dense, lush turf with a medium texture and rich medium-to-dark green color. Unmowed height reaches 18 to 24 inches, typically maintained at 1.5 to 2.5 inches. Produces characteristic pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium width (2-4mm), flat to folded with prominent parallel veins and distinctive boat-shaped tips. Folded vernation in the bud. Ligule is short and membranous, auricles absent.
Root System
Fibrous root system with extensive underground rhizomes. Moderate depth (6-12 inches), moderate establishment speed from seed, and forms a very strong, dense sod with a moderate tendency to build thatch.
Growing Information
Origin Region
Europe, northern Asia, and parts of the mountainous regions of North America; widely cultivated globally in temperate climates
Growth Habit
Rhizomatous with aggressive underground spreading, forming a very dense, uniform turf mat
Sunlight & Water Needs
Performs best in full sun (minimum 6 hours of direct sunlight); moderate shade tolerance. High watering needs during dry spells to maintain green color, enters dormancy during severe drought. Prefers well-drained loamy soils with pH 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires regular mowing, moderate-to-high fertilization (3-5 lbs N per 1000 sq ft annually), periodic aeration and dethatching, and high maintenance overall.
Special Characteristics
Good wear tolerance and excellent self-repairing capability via rhizomes. Moderate shade tolerance, good winter color retention in milder climates, high drought recovery ability through summer dormancy.
Ecological Information
Widely naturalized in North America. Provides good soil stabilization and erosion control, forms dense turf that filters runoff water, commonly blended with perennial ryegrass and fine fescues.