Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common lawn-type cultivars (likely a blend including 'Midnight' or 'Baron' given its usage)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters semi-dormancy during hot, dry summer periods
About This Grass
A dark-green, medium-textured turf grass that forms a lush carpet. If unmowed, it reaches 12-24 inches with open, pyramidal seed heads (panicles); in lawns, it is kept dense and uniform.
Blade Characteristics
Boat-shaped tips (v-shaped), 2-4mm wide, smooth surfaces, prominent midrib, folded vernation in the bud, short membranous ligule, no auricles
Root System
Moderately shallow fibrous system with extensive rhizomes; moderate thatch builder; slow to establish from seed but forms a very durable sod
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco and Algeria; best adapted to Northern US and Canada
Growth Habit
Rhizomatous; forms a thick, dense sod by spreading via underground stems (rhizomes)
Sunlight & Water Needs
Full sun preferred (at least 6 hours); moderate shade tolerance; high water needs (1-1.5 inches per week) to maintain green color during summer
Mowing & Maintenance
2.0 to 3.5 inches; frequent mowing needed during spring/fall peaks; requires 2-4 lbs Nitrogen per 1000 sq ft annually; medium to high maintenance
Special Characteristics
Excellent self-repairing ability due to rhizomes; high wear tolerance; susceptible to summer patch and necrotic ring spot; superior winter color
Ecological Information
Introduced/Naturalized in North America; provides cover for small mammals; excellent for soil erosion control due to sod-forming habit; commonly mixed with Perennial Ryegrass and Fine Fescue