Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Likely a common turf-type variety such as 'Midnight' or 'Kenblue' (common in mixed lawns)
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance but struggles in the heat of Zone 8 and above without significant irrigation.
About This Grass
A dense, low-growing turf grass with a dark blue-green color. It forms a uniform carpet-like surface when mowed. Unmowed, it can reach 12-24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Fine to medium width (2-4mm), V-shaped or flat, featuring a distinct boat-shaped tip. Ligule is very short and membranous; auricles are absent. Vernation is folded in the bud.
Root System
Relatively shallow fibrous root system with extensive horizontal rhizomes. High thatch tendency due to rhizome density; moderate establishment speed but excellent sod-forming capability.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Morocco and Algeria; widely adapted to temperate climates
Growth Habit
Rhizomatous (spreading underground), forming a dense, thick sod
Sunlight & Water Needs
Prefers Full Sun (6+ hours) but can tolerate partial shade; high water requirement (approx. 1 inch per week). Sensitive to heat and severe drought, entering dormancy to survive.
Mowing & Maintenance
Ideal height 2.0-3.5 inches. High maintenance: requires 2-4 lbs Nitrogen/1000 sq ft annually, regular dethatching, and core aeration.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; moderate salt tolerance.
Ecological Information
Introduced and naturalized in North America. Provides habitat for small insects and some nesting birds when long. Often blended with Perennial Ryegrass or Fine Fescue for improved resilience.