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 or mixed turf cultivars (e.g., 'Midnight', 'Baron')
Hardiness Zones
USDA Hardiness Zones 3 to 7, tolerates cold winters very well down to -40F, but struggles with extreme summer heat unless irrigated.
About This Grass
Forms a dense, high-quality turf with a fine to medium texture and an attractive dark green to blue-green color. Mowed height is typically 1.5 to 2.5 inches, while unmowed growth can reach 18 to 24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded with distinct boat-shaped tips and parallel veins. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous root system with moderate depth (6-12 inches). Moderate thatch-forming tendency, slow to establish from seed, but forms an exceptionally dense, tough sod that recovers well from wear via rhizomes.
Growing Information
Origin Region
Europe, Northern Asia, and parts of the mountains of North America; widely cultivated throughout cool-temperate regions worldwide.
Growth Habit
Rhizomatous, spreading underground via extensive horizontal root stocks to form a dense, uniform turf.
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily) for best performance, though some cultivars have moderate shade tolerance. High water needs during dry spells; goes into summer dormancy if unwatered. Prefers well-drained fertile soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Moderate to high maintenance level. Requires regular fertilization (3-4 lbs N per 1000 sq ft annually), frequent mowing during spring and fall, and periodic aeration/dethatching.
Special Characteristics
Excellent traffic and wear tolerance due to rhizomatous spreading. Good cold hardiness and winter color retention in milder winters. Moderate disease susceptibility (e.g., leaf spot, dollar spot, summer patch). Excellent erosion control.
Ecological Information
Introduced to North America by early European settlers. Provides low wildlife food value compared to native grasses, but excellent for soil stabilization, carbon sequestration, urban cooling, and stormwater filtration.