Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 carbon fixation
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Common or 'Midnight' type based on dark green hue and medium blade width
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; performs poorly in high-heat humid climates without irrigation.
About This Grass
A dense, cool-season grass with a soft, uniform texture and dark green color. It forms a lush carpet and is highly valued for its ability to go dormant during heat and recover via rhizomes in fall.
Blade Characteristics
Blade width: medium (2-4mm); shape: flat or slightly V-shaped; tip: distinctive boat-shaped (blunt); color: rich dark green to blue-green; vernation: folded in the bud; ligule: short, membranous; auricles: absent.
Root System
Moderately deep fibrous root system complemented by extensive rhizomes. Moderate thatch tendency; slow to moderate establishment from seed but forms a very strong sod.
Growing Information
Origin Region
Native to Europe, North Asia, and Morocco; widely adapted across temperate Northern Hemisphere and transition zones
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, self-repairing sod mat
Sunlight & Water Needs
Full Sun preferred (6+ hours); moderate shade tolerance. High water needs during peak growth, but has excellent drought dormancy capabilities. Prefers well-drained soil with pH 6.0-7.5.
Mowing & Maintenance
Ideal height 2.0 to 3.5 inches. High maintenance level; requires 2-4 lbs Nitrogen per 1000 sq ft annually and semi-annual core aeration to manage thatch.
Special Characteristics
High wear tolerance and recovery due to rhizomes; susceptible to leaf spot, melting out, and necrotic ring spot; moderate salt tolerance; excellent aesthetic appeal.
Ecological Information
Introduced/Naturalized in North America; provides soil stabilization for erosion control; works well in mixtures with Perennial Ryegrass and Fine Fescue for biodiversity and resilience.