Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Standard or common blend (e.g., 'Midnight', 'Baron')
Hardiness Zones
Thrives in USDA Hardiness Zones 3-7, handles cold winters exceptionally well, goes dormant in extreme summer heat, well-suited to northern regions and cool transition zones
About This Grass
Forms a dense, fine to medium-textured turf with a vibrant medium to dark green color; spreads via underground rhizomes creating a tight sod; height reaches 1.5 to 2.5 inches when maintained, and up to 18-24 inches if unmowed with a panicle seed head
Blade Characteristics
Blades are medium-fine (2-4mm width), flat or slightly folded, with characteristic boat-shaped tips and prominent parallel veins giving a tramline appearance; folded in the bud (vernation); membranous short ligule, no auricles
Root System
Moderately deep fibrous root system combined with extensive underground rhizomes; moderate establishment speed; forms a very dense sod with a tendency to build up thatch over time
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 aggressive creeping roots to form a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily), moderate to high water needs for optimal appearance, goes into summer dormancy during severe drought, prefers well-drained fertile soils with a pH of 6.0-7.0
Mowing & Maintenance
Mow at 2.0 to 3.5 inches height; regular mowing during active spring/fall growth; fertilization needs are moderate to high (3-4 lbs N per 1000 sq ft annually); requires periodic dethatching and aeration; high maintenance level
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; moderate shade tolerance; susceptible to summer patch, dollar spot, and leaf spot; excellent winter color retention in milder cool-season climates
Ecological Information
Introduced species in North America; provides soil stabilization and erosion control through dense root mat; filters runoff water effectively; commonly blended with perennial ryegrass and fine fescues