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 Elite-type Kentucky Bluegrass (e.g., 'Midnight', 'Merion', 'Prudential')
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the deep South; enters winter dormancy and may go summer dormant in extreme heat.
About This Grass
A dense, high-quality turf grass known for its dark green color and medium-to-fine texture. It typically reaches 6 to 12 inches if unmowed, exhibiting a spreading, uniform growth habit and panicle seed heads.
Blade Characteristics
Blade width: 2-4mm (medium-fine); Shape: V-shaped or flat; Tip: Distinctive boat-shaped (keeled) tip; Color: Dark green to blue-green; Vernation: Folded in the bud; Ligule: Very short, membranous; Auricles: Absent
Root System
Moderately shallow (mostly top 6-8 inches) but dense and fibrous; extensive rhizome network allows for excellent recovery and thatch formation.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; highly adapted to northern temperate climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod mat
Sunlight & Water Needs
Prefers Full Sun (minimum 6 hours); moderate shade tolerance in some cultivars. High water needs; requires consistent moisture to stay green in summer; enters dormancy during severe drought.
Mowing & Maintenance
Ideal height: 2.0-3.5 inches; Maintenance: High; requires frequent mowing and 2-4 lbs Nitrogen per 1000 sq ft annually; requires regular aeration due to thatch.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; high turf density crowds out weeds; susceptible to dollar spot and summer patch; moderate salt tolerance.
Ecological Information
Introduced and naturalized across North America; provides soil stabilization for erosion control; serves as habitat/food for various lepidoptera larvae and small birds; often blended with Tall Fescue or Perennial Ryegrass.