Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 pathway
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Pasture, and Erosion Control
Variety / Cultivar
Common-type (likely non-specified cultivar such as Kenblue or a wild-type local ecotype)
Hardiness Zones
USDA Zones 2-7; extremely cold-tolerant but struggles in the heat of the Deep South (Zones 8-11) unless grown at high altitudes.
About This Grass
A medium-textured, low-to-medium height perennial grass. It exhibits a rich emerald to blue-green color. When mowed, it creates a dense, uniform carpet; when unmowed, it produces open, branched panicle seed heads (3-8 inches).
Blade Characteristics
Blade width is medium (2-4mm). The most distinctive feature is the boat-shaped (V-shaped) leaf tip. Vernation is folded in the bud. Leaves are dark green, smooth on both sides, with a prominent midrib and twin 'railroad tracks' (transparent lines) visible when held to light. Ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous. Most roots are shallow (top 6-10 inches), but the rhizomes allow for excellent sod strength and recovery from traffic or damage. Forms significant thatch if over-fertilized.
Growing Information
Origin Region
Europe, Northern Asia, and the mountains of Morocco; widely adapted to temperate climates worldwide.
Growth Habit
Rhizomatous (spreading underground); forms a dense sod/mat via strong creeping underground stems.
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) but has moderate shade tolerance. High water requirements; enters summer dormancy during extended drought to survive. Prefers well-drained fertile soils with pH 6.0-7.2.
Mowing & Maintenance
Ideal height 2.0-3.5 inches. High maintenance level. Requires 2-4 lbs Nitrogen per 1000 sq ft annually. Needs periodic aeration and dethatching to manage the sod layer.
Special Characteristics
Exceptional wear tolerance and recovery due to rhizomes. Susceptible to Leaf Spot, Dollar Spot, and necrotic ring spot. Excellent winter hardiness and beautiful dark green color.
Ecological Information
Introduced and naturalized in North America. Provides forage for livestock and nesting cover for small birds. Excellent at preventing soil erosion due to dense rhizome network. Commonly blended with Perennial Ryegrass or Fine Fescue.