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 (fairways and tees)
Variety / Cultivar
General species type, widely cultivated varieties include 'Midnight', 'Bewitched', and 'Baron'
Hardiness Zones
USDA Hardiness Zones 3 to 7 (thrives best in cool, humid or irrigated arid regions); excellent cold tolerance, survives harsh winters under snow cover.
About This Grass
Forms a dense, high-quality turf with a vibrant medium to dark green color. It grows up to 18-24 inches if unmowed, but is typically maintained at 1.5 to 2.5 inches. Fine to medium texture with pyramidal, open panicle seed heads at maturity.
Blade Characteristics
Blades are medium-narrow (2-4mm), flat or folded in the bud (Vernation: folded), with distinctive boat-shaped tips. Prominent parallel veins with a light-colored midrib and two clear translucent lines. Ligule is short and membranous; auricles are absent.
Root System
Moderately deep fibrous root system combined with extensive rhizomes, creating a dense sod that minimizes erosion. Moderate to slow establishment speed from seed, but excellent recovery from wear via rhizomes.
Growing Information
Origin Region
Native to Europe, northern Asia, and parts of the mountains in North America; widely naturalized and cultivated across temperate regions worldwide
Growth Habit
Aggressively rhizomatous, forming a dense, uniform turf mat with underground creeping stems
Sunlight & Water Needs
Requires full sun (at least 6-8 hours daily) for optimal growth, with moderate to high water needs. Good winter hardiness and moderate drought tolerance, entering dormancy during prolonged dry spells.
Mowing & Maintenance
Ideal mowing height is 1.5 to 2.5 inches. High maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft annually), frequent mowing during peak spring/fall growth, and periodic aeration and dethatching.
Special Characteristics
High wear and traffic tolerance once established due to rhizomatous recovery. Good disease resistance depending on the cultivar (susceptible to dollar spot, leaf spot, and summer patch). Excellent winter color retention in milder cool regions.
Ecological Information
Introduced species in North America; provides standard turf ecological functions including soil stabilization, carbon sequestration, and minor wildlife foraging. Frequently blended with Perennial Ryegrass and Fine Fescues in cool-season seed mixes.