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 of turf-type cultivars (e.g., 'Midnight', 'Bewitched')
Hardiness Zones
USDA Hardiness Zones 3 through 7, highly cold tolerant, goes dormant in freezing winters, suffers in extreme prolonged summer heat.
About This Grass
Forms a dense, high-quality turf with a medium-fine texture and rich medium to dark green or blue-green color. Matures up to 18-24 inches if unmowed, but maintained at 1.5-2.5 inches. Features open, pyramidal panicle seed heads.
Blade Characteristics
Medium width (2-4mm), flat to folded shape with distinctive boat-shaped tips and parallel veins. Vernation is folded in the bud. Ligule is short and membranous, auricles are absent, and the collar is broad and continuous.
Root System
Moderately deep fibrous root system combined with aggressive rhizomes, creating a dense sod. Moderate thatch-forming tendency; slow to germinate and establish from seed.
Growing Information
Origin Region
Europe and Northern Asia, widely naturalized and cultivated across North America and temperate regions worldwide
Growth Habit
Rhizomatous, spreading extensively via underground stems to form a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6 hours daily) but exhibits moderate shade tolerance depending on the cultivar. High water needs during hot dry spells; goes into summer dormancy (turning brown) during severe drought.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches height. Requires moderate to high maintenance, including regular fertilization (3-4 lbs N per 1000 sq ft annually), periodic aeration, and dethatching.
Special Characteristics
Excellent traffic and wear tolerance due to aggressive rhizomatous recovery, good cold tolerance, fair to moderate drought recovery, low shade tolerance compared to fescues.
Ecological Information
Introduced species in North America. Provides good soil stabilization and erosion control through dense sod, often mixed with Perennial Ryegrass and Tall Fescue for home lawns and athletic fields.