Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common blend, often mixed with other cool-season turf types
Hardiness Zones
USDA Hardiness Zones 3 to 7; excellent cold tolerance, surviving harsh winters; goes dormant during hot, dry summer periods; widely used in northern climates.
About This Grass
Medium-textured turfgrass forming a dense, resilient carpet; brilliant medium to dark green color during active growth seasons; enters summer dormancy and turns brown during extreme heat and drought stress; reaches 1.5 to 2.5 inches when maintained, taller if unmowed, featuring open panicle seed heads at maturity.
Blade Characteristics
Medium width (2-4mm), flat to folded with distinct parallel veins and characteristic boat-shaped tips; vernation is folded in the bud; membranous ligule with no auricles.
Root System
Moderately deep fibrous root system combined with aggressive rhizomes; forms a very dense sod that resists wear and erosion; moderate to slow establishment speed; moderate tendency to form thatch under high fertilization.
Growing Information
Origin Region
Europe and Northern Asia, widely naturalized and cultivated across North America and temperate regions
Growth Habit
Rhizomatous, spreading underground via robust rhizomes to form a dense, uniform sod
Sunlight & Water Needs
Requires full sun (minimum 6 hours of direct sunlight) for optimal performance; moderate to high watering needs during dry spells; fair to good drought tolerance by entering summer dormancy; prefers well-drained, fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height between 2.0 to 3.0 inches; requires regular mowing during spring and fall; fertilization needs are medium to high (3-4 lbs N per 1000 sq ft annually); regular dethatching and aeration needed; high overall maintenance level.
Special Characteristics
Good wear tolerance and excellent self-repairing capabilities due to rhizomes; susceptible to certain diseases like dollar spot, melting-out, and summer patch; poor shade tolerance compared to fine fescues; high ability to crowd out weeds when healthy.
Ecological Information
Introduced species in North America; provides standard turf ecological functions and erosion control; low wildlife food value compared to native prairie species; commonly blended with perennial ryegrass and tall fescue in northern lawn seed mixes.