Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 carbohydrate metabolism
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Fairway
Variety / Cultivar
High-density turf-type (similar to 'Midnight' or 'Baron' varieties)
Hardiness Zones
USDA Hardiness Zones 2-7. Excellent cold tolerance; enters winter dormancy and turns brown/straw-colored during deep freezes; moderate heat tolerance but enters semi-dormancy in extreme summer heat.
About This Grass
A dense, lush green grass with an upright growth habit. It features a rich, dark-green to blue-green color. When mowed, it provides a smooth, uniform surface; if unmowed, it reaches 12-24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Fine to medium width (2-4mm). Blades are flat or slightly folded with a distinctive boat-shaped (keeled) tip. Vernation is folded in the bud; the ligule is very short and membranous; auricles are absent. The upper surface is often smooth with a prominent mid-vein.
Root System
Moderate depth (primarily in the top 6-8 inches). Fibrous root system with strong rhizomes that promote thick thatch and excellent sod strength. High establishment speed from seed compared to some fescues, but slower than ryegrass.
Growing Information
Origin Region
Native to Europe, Northern Asia, and North Africa; widely adapted to northern temperate climates and transition zones
Growth Habit
Rhizomatous (underground spreading). Forms a very dense, carpet-like sod that can self-repair through its extensive network of rhizomes.
Sunlight & Water Needs
Prefers Full Sun (6+ hours); moderate shade tolerance. High water requirements; requires regular irrigation to stay green during summer. Prefers well-drained, fertile soils with a pH between 6.0 and 7.5.
Mowing & Maintenance
Ideal mowing height: 2.0-3.5 inches. Mowing frequency: 1-2 times weekly. Fertilization: High (2-4 lbs Nitrogen per 1000 sq ft per year). Requires periodic dethatching and aeration due to rhizome density.
Special Characteristics
High traffic/wear tolerance due to rhizomes; excellent recovery from injury. Susceptible to Leaf Spot and Dollar Spot in high humidity. Very popular for home lawns and sports fields due to its high density and aesthetic appeal.
Ecological Information
Introduced and naturalized in North America. Provides erosion control through dense sod formation. Offers cover and nesting sites for small birds and insects. Widely used in 'Northern Mixes' alongside Fine Fescues and Perennial Ryegrass.