Kentucky Bluegrass
Poa pratensis · Cool-season Perennial; C3 photosynthesis
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Fairways
Variety / Cultivar
Common/Mixed Cultivar (e.g., likely a blend containing 'Midnight' or similar Elite types)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; semi-dormant in winter (turns straw-colored in extreme cold).
About This Grass
A fine to medium textured grass with a rich dark green to blue-green color. It forms a dense, velvet-like carpet when healthy. Seed heads are open, airy panicles (pyramidal shape) but rarely seen in maintained lawns.
Blade Characteristics
2-4mm width; folded vernation; distinct boat-shaped tip (keeled); smooth surfaces with a dual mid-vein visible as 'track marks'; ligule is short, membranous, and truncated; auricles are absent.
Root System
Relatively shallow fibrous root system with extensive horizontal rhizomes; high thatch tendency; slow to establish from seed but excellent at self-repairing thin spots via sod-forming growth.
Growing Information
Origin Region
Native to Europe, North Asia, and North Africa; widely naturalized in North America and cool temperate climates
Growth Habit
Rhizomatous; forms a thick, dense sod by spreading through underground runners (rhizomes)
Sunlight & Water Needs
Full Sun preferred (6+ hours); moderate shade tolerance in some cultivars; high water requirements (1-1.5 inches per week); enters summer dormancy during severe drought/heat.
Mowing & Maintenance
1.5 to 3.5 inches; high maintenance; requires 2-5 lbs Nitrogen per 1000 sq ft annually; needs regular dethatching and core aeration to manage sod density.
Special Characteristics
Excellent wear tolerance and recovery; produces high-quality sod; good disease resistance in elite cultivars but susceptible to leaf spot and dollar spot; moderate salt tolerance.
Ecological Information
Introduced and naturalized in North America; provides forage for various wildlife; stabilizes soil efficiently due to rhizomes; often mixed with Perennial Ryegrass or Fine Fescues to improve shade and disease range.