Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Erosion Control
Variety / Cultivar
Common Kentucky Bluegrass (likely a mixed turf variety)
Hardiness Zones
USDA Hardiness Zones 2 through 7. Excellent cold tolerance; enters winter dormancy; susceptible to heat stress in Southern climates.
About This Grass
A medium-textured, high-density turfgrass known for its rich emerald to dark green color. It typically grows 12 to 24 inches tall if left unmowed, featuring a panicle seed head shaped like a pyramid. It goes dormant and brown during hot, dry summer months but recovers quickly in fall.
Blade Characteristics
Blade width is medium (2-4mm), featuring a distinct boat-shaped (V-shaped) tip. The vernation is folded in the bud. Leaves are smooth on both sides with a prominent center vein (midrib). Ligule is very short and membranous; auricles are absent.
Root System
Moderately deep but concentrated in the top 6-8 inches of soil. Extensive rhizomes create a thick thatch layer and allow for excellent self-repair and wear recovery. Establishment is slow from seed.
Growing Information
Origin Region
Native to Europe, North Asia, and Northern Africa; widely naturalized across North America and temperate regions.
Growth Habit
Rhizomatous (spreading via underground creepers); forms a thick, dense sod and mat-like covering.
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) but has moderate shade tolerance. Requires high water levels (approx. 1 inch per week) and prefers well-drained, fertile soils with a pH of 6.0-7.5.
Mowing & Maintenance
Ideal height is 2.5 to 3.5 inches. High maintenance level: requires frequent mowing and regular fertilization (3-5 lbs N per 1000 sq ft annually). Needs periodic dethatching and aeration.
Special Characteristics
Exceptional wear tolerance due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; high salt sensitivity; dormant during drought but stays alive via rhizomes.
Ecological Information
Introduced in North America; provides forage for various wildlife and stabilizing cover for songbirds. Efficient at soil stabilization and erosion control on sloped landscapes. Often blended with Perennial Ryegrass or Tall Fescue.