Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Improved Type (e.g., 'Midnight' or 'Baron' typical for home lawns)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor performance in high heat/humidity of the deep South; enters winter dormancy.
About This Grass
A dense, carpet-like grass with a rich dark green to blue-green color; grows 12-24 inches if unmowed; produces panicle seed heads late in the season.
Blade Characteristics
Fine to medium width (2-4mm), folded vernation, distinctive boat-shaped (V-shaped) leaf tips, smooth texture, short membranous ligule, no auricles.
Root System
Relatively shallow but dense fibrous root system with extensive rhizomes; forms thick thatch; slow establishment but excellent sod knitting.
Growing Information
Origin Region
Native to Europe, North Asia, and Morocco; naturalized throughout North America
Growth Habit
Rhizomatous (spreading underground), forming a dense, self-repairing sod mat
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate to high water needs; goes dormant during severe drought/heat; prefers well-drained soil pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.5-3.5 inches; high maintenance; requires 2-4 lbs N/1000 sq ft per year; regular dethatching and aeration needed.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; good disease resistance in improved cultivars; susceptible to summer patch and necrotic ring spot.
Ecological Information
Introduced/Naturalized; provides some cover for small wildlife; excellent for soil erosion control due to sod density; often blended with Fine Fescue in shaded areas (as seen under the tree canopy).