Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common blend (such as 'Midnight' or 'Baron' types)
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7, highly cold tolerant, but struggles in extreme southern heat unless heavily irrigated.
About This Grass
Forms a dense, medium-textured turf with a rich dark green to blue-green color. Mown height typically ranges from 2 to 3 inches, while unmown plants can reach 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Medium width (2-4mm), flat to folded with prominent parallel veins and distinctive boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous, and auricles are absent.
Root System
Moderately deep fibrous root system combined with extensive rhizomes. Moderate establishment speed from seed, but forms an exceptionally tough and dense sod that recovers well from wear.
Growing Information
Origin Region
Native to Europe, northern Asia, and parts of North America; widely cultivated throughout cool-temperate regions worldwide
Growth Habit
Rhizomatous, spreading underground via aggressive creeping rhizomes to form a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) for best performance, though some cultivars offer moderate shade tolerance. High watering needs during dry spells to maintain green color; goes into summer dormancy if unwatered.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires moderate to high maintenance, including regular fertilization (3-4 lbs N per 1,000 sq ft annually), frequent mowing, and periodic aeration or dethatching.
Special Characteristics
Excellent wear tolerance and self-repairing capability due to aggressive rhizomes. Good cold tolerance, moderate drought recovery via dormancy, and average disease resistance depending on the specific cultivar.
Ecological Information
Introduced species in North America widely used for erosion control and turf. Provides limited wildlife value compared to native prairies, but excellent for carbon sequestration and cooling urban microclimates when well-maintained.