Kentucky Bluegrass
Poa pratensis · Cool-season (C3), Perennial
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common lawn mix Kentucky Bluegrass (unspecified cultivar)
Hardiness Zones
USDA Hardiness Zones 3 through 7; thrives in cool, humid climates and transition zone elevations.
About This Grass
A medium-textured, cool-season grass that produces a lush, dark green carpet. It enters dormancy during hot, dry periods and is known for its high-quality appearance and dense growth habit. The seed heads are open, airy panicles with a pyramidal shape.
Blade Characteristics
Blade width is medium (2-4mm). The most distinctive feature is the boat-shaped (keeled) tip. The vernation is folded in the bud, and the ligule is short and membranous. Many blades show two clear translucent lines (midribs) parallel to each other.
Root System
Moderately shallow fibrous root system with extensive horizontal rhizomes. It forms a dense, strong sod that resists traffic well, though it has moderate thatch production.
Growing Information
Origin Region
Europe, Northern Asia, and the mountains of Morocco and Algeria; widely naturalized in North America
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense sod and spreading readily into bare spots
Sunlight & Water Needs
Prefers full sun but can tolerate light shade; requires approximately 1 inch of water per week; moderate drought tolerance as it survives by entering dormancy during extreme heat.
Mowing & Maintenance
Ideal mowing height is 2.5 to 3.5 inches. High maintenance requirements; needs consistent fertilization (3-5 lbs N per 1000 sq ft annually) and regular irrigation to maintain green color.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; high aesthetic value.
Ecological Information
Introduced/Naturalized status in North America; provides forage for various insects and small mammals; excellent for soil erosion control due to dense sod formation; often mixed with Perennial Ryegrass and Fine Fescue.