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 blend or standard turf-type cultivars like 'Midnight' or 'Baronie'
Hardiness Zones
USDA Hardiness Zones 3-7, highly cold-tolerant with winter dormancy, struggles in extreme summer heat unless irrigated.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and a rich medium to dark green color. Reaches up to 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Features open, pyramidal panicle seed heads at maturity in late spring.
Blade Characteristics
Medium-fine width (2-3mm), flat to folded shape with distinctive boat-shaped tips and prominent parallel veins giving a railroad-track appearance. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system combined with extensive rhizomes. Moderate thatch-forming tendency under high fertility and watering. Establishes slowly from seed but forms an extremely tough, wear-resistant sod.
Growing Information
Origin Region
Europe and Northern Asia; widely naturalized and cultivated across North America and temperate regions worldwide, performing best in northern climates.
Growth Habit
Rhizomatous, producing underground stems that allow it to spread and form a dense, uniform sod with medium-high spreading rate.
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) with moderate to high water needs. Good drought dormancy capability, recovering well upon receiving moisture. Prefers well-drained fertile loam soils with a pH of 6.0-7.0.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches regularly. Requires medium-high maintenance including 2-4 lbs N per 1000 sq ft annually, regular irrigation, and periodic dethatching/aeration.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomatous spreading. Good cold hardiness, moderate heat and shade tolerance. Prone to certain diseases like dollar spot and leaf spot under high humidity.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control, filters runoff water, widely used in blends with perennial ryegrass and fescue, and offers limited wildlife cover.