Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Fairways
Variety / Cultivar
Common or Elite Cultivar (e.g., 'Midnight', 'Mazama', or 'Blueberry')
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; enters winter dormancy and turns brown in extreme cold.
About This Grass
A medium-textured turfgrass with a characteristic dark green to blue-green color. It forms a lush, carpet-like lawn. In un-mowed states, it reaches 12-24 inches with open, pyramidal panicle seed heads.
Blade Characteristics
Blade width: 2-4mm (medium); Shape: V-shaped or flat; Tip: Distinctive boat-shaped (keeled) tip; Color: Dark emerald to blue-green; Vernation: Folded in the bud; Ligule: Short, membranous, truncate; Auricles: Absent; Collar: Narrow to medium, divided by midrib.
Root System
Moderately shallow fibrous roots supported by extensive rhizomes; slow to establish from seed but forms a powerful, dense sod once mature; moderate thatch-forming tendency.
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco and Algeria; widely adapted to temperate climates worldwide
Growth Habit
Rhizomatous (underground spreading stems) that form a dense, knit sod
Sunlight & Water Needs
Full sun preferred (6-8 hours); poor shade tolerance. High water needs, requiring 1-1.5 inches per week. Goes dormant during extreme drought but survives via rhizomes.
Mowing & Maintenance
Mowing height: 2.0-3.5 inches; Frequency: Weekly during growing season; Fertilization: High (3-5 lbs N per 1000 sq ft annually); High maintenance level due to water and nutrient demands.
Special Characteristics
Self-repairing ability through rhizomes; excellent wear tolerance for foot traffic; prone to Summer Patch and Necrotic Ring Spot; low salt tolerance; high aesthetic quality.
Ecological Information
Introduced/Naturalized in North America; provides cover for small mammals; stabilizing sod prevents erosion; often blended with Perennial Ryegrass or Fine Fescue for improved resilience.