Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common or Generic Kentucky Bluegrass (often mixed with other cool-season varieties like Fine Fescue in large residential lawns)
Hardiness Zones
USDA Zones 2-7; highly cold-tolerant but struggles in the heat of the Deep South. Enters winter dormancy when ground freezes.
About This Grass
A dense, low-growing turf with a rich green to dark green color. When unmowed, it can reach 12-24 inches, but is typically maintained at 2-3 inches. It features a fine to medium texture and distinctive boat-shaped seed heads (panicles) during its reproductive phase in late spring.
Blade Characteristics
Blade width is medium (2-4mm). Features a smooth surface with a prominent mid-vein and a unique boat-shaped tip. Vernation is folded in the bud; ligule is very short and membranous; auricles are absent.
Root System
Produces a shallow to moderately deep fibrous root system combined with strong rhizomes that create a dense thatch layer. This allows for excellent sod strength and recovery from wear, though it requires more water during drought than deeper-rooted fescues.
Growing Information
Origin Region
Europe, Northern Asia, and the mountains of Morocco and Algeria; best adapted to cool, humid climates
Growth Habit
Rhizomatous (spreading via underground stems), forming a thick, dense sod with a moderate rate of spread
Sunlight & Water Needs
Prefers full sun (minimum 6 hours) but has moderate shade tolerance. Requires consistent moisture (approx. 1 inch per week). It will go dormant (brown) during extended hot, dry periods as a survival mechanism.
Mowing & Maintenance
Ideal height is 2.5–3.5 inches. Needs regular mowing during peak spring/fall growth. Requires 2-4 lbs of Nitrogen per 1000 sq ft per year. High maintenance level due to water and fertilizer needs.
Special Characteristics
Excellent self-repair ability due to rhizomes. Good traffic tolerance once established. Moderately susceptible to Leaf Spot, Melting Out, and Summer Patch diseases. Popular for its barefoot feel and uniform appearance.
Ecological Information
Introduced and naturalized across North America. Provides soil stabilization and filtration. While not native, it is a staple of suburban landscapes. Often mixed with Perennial Ryegrass for faster establishment or Fine Fescue for shade performance.