Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
AI-generated identification · may be incorrect
Grass Category
Lawn/Turf Grass, Sports Turf
Hardiness Zones
USDA Hardiness Zones 3 to 7 (thrives in northern temperate climates with cold winters and moderate summers). Excellent cold tolerance; enters dormancy during extreme summer heat.
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Variety / Cultivar
General species (commonly cultivars like 'Midnight' or 'Baron')
About This Grass
Forms a dense, fine-to-medium-textured turf with an attractive rich green to blue-green color during the active growing season. Shows significant winter dormancy where the blades turn tan or straw-colored. Height when maintained is typically 1.5 to 2.5 inches, but can reach 18-24 inches when unmowed, featuring open, pyramid-shaped panicle seed heads.
Blade Characteristics
Blades are fine to medium in width (2-4mm), flat to folded with distinct parallel veins and characteristic 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 vigorous rhizomes that form a very tough, dense sod. Slow to establish from seed, but exhibits moderate to high thatch tendencies under high fertility and watering.
Growing Information
Origin Region
Europe and northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading extensively underground to form a dense, uniform sod
Sunlight & Water Needs
Requires full sun to partial shade (minimum 4-6 hours of direct sunlight). High water requirement to maintain active growth during summer; enters summer dormancy or wilts quickly under drought unless irrigated. Prefers well-drained, fertile soils with a pH between 6.0 and 7.0.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Requires frequent mowing during spring and fall peaks. High maintenance level requiring 2-4 lbs N per 1000 sq ft annually, regular aeration, and occasional dethatching.
Special Characteristics
Exceptional traffic and wear tolerance due to aggressive self-repair via rhizomes. Good cold tolerance, moderate shade tolerance compared to fine fescues, and slow recovery from severe drought unless irrigated.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control through dense root and rhizome networks. Frequently blended with Perennial Ryegrass and Tall Fescue in turf seed mixes.