Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3
Grass Family
Poaceae, subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common blend / Unknown specific cultivar
Hardiness Zones
USDA Hardiness Zones 3 to 7. Excellent cold tolerance, struggles in extreme summer heat unless irrigated.
About This Grass
Forms a dense, fine-to-medium textured carpet of medium to dark green or blue-green turf. Height ranges from 1.5 to 2.5 inches when maintained, but can reach 18 to 24 inches if unmowed with a panicle-type seed head.
Blade Characteristics
Blades are medium width (2-4mm), flat or folded, with distinct boat-shaped tips and parallel sides. Vernation is folded in the bud. Ligule is short and membranous, auricles absent, with a broad collar region.
Root System
Moderately deep fibrous root system combined with vigorous underground rhizomes. Tends to build thatch over time. Moderate establishment speed from seed.
Growing Information
Origin Region
Europe, northern Asia, and the mountains of North America; widely cultivated across temperate regions globally.
Growth Habit
Aggressively rhizomatous, forming a dense sod and tight turf mat.
Sunlight & Water Needs
Requires full sun (minimum 6 hours direct sunlight), though some cultivars have moderate shade tolerance. High water requirements to stay green during summer, though it enters dormancy during severe drought.
Mowing & Maintenance
Ideal mowing height is 2.0 to 3.0 inches. Medium-high maintenance level requiring regular fertilization (2-4 lbs N/1000 sq ft/year), periodic dethatching, and aeration.
Special Characteristics
Exceptional wear tolerance and self-repairing capability due to rhizomes. Good winter color retention in cooler regions. Prone to certain diseases like dollar spot and leaf spot under high humidity.
Ecological Information
Widely naturalized in North America. Provides good soil stabilization and erosion control. Often blended with perennial ryegrass and fescues in turf seed mixes.