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 Grass
Variety / Cultivar
Common or various improved cultivars like 'Midnight' or 'Compact', known for rich dark green color and dense sod formation.
Hardiness Zones
USDA Hardiness Zones 3 to 7, performs exceptionally well in the northern tier of the US and Canada.
About This Grass
Forms a dense, fine-to-medium textured turf with an attractive blue-green to dark green color. Reaches up to 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Medium-fine width (2-4mm), flat to folded shape with distinctive boat-shaped tips. Vernation is folded in the bud. Color ranges from medium to dark blue-green. Features prominent parallel veins on the upper surface with a smooth underside. Ligule is short and membranous, auricles are absent.
Root System
Moderate depth (typically 4-6 inches, occasionally deeper), highly fibrous and rhizomatous. Forms a very dense sod that resists weed invasion. Moderate establishment speed, prone to thatch buildup under high maintenance.
Growing Information
Origin Region
Native to Europe, northern Asia, and parts of the mountains of North America. Widely cultivated throughout the northern United States, Canada, and cool temperate regions worldwide.
Growth Habit
Rhizomatous, spreading aggressively via underground stems to form a dense, uniform turf mat.
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily), with moderate to high water needs. Has good winter hardiness and enters summer dormancy during severe drought, recovering well when moisture returns.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches. Requires regular fertilization (3-4 lbs N per 1000 sq ft annually) and moderate to high maintenance level, including periodic dethatching and aeration.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomatous spread and self-repairing capability. Good cold and winter color retention in milder cool regions, moderate shade tolerance (prefers full sun).
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control through its dense root and rhizome network. Commonly mixed with Perennial Ryegrass and Fine Fescues in northern lawn seed blends.