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 Elite Blend (e.g., 'Midnight' or 'Baron' type)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; enters dormancy (turns brown) during extreme heat or drought.
About This Grass
A dense, soft turf grass that exhibits a dark blue-green color when healthy. In this image, it shows severe summer dormancy (straw-colored patches) due to drought or heat stress. Seed heads are open, airy panicles (not visible here due to mowing).
Blade Characteristics
Fine to medium width (2-4mm); V-shaped or flat; boat-shaped tips (distinctive); folded in the bud (vernation); ligule is short and membranous; no auricles present.
Root System
Relatively shallow fibrous root system with extensive rhizomes; allows for excellent sod formation and recovery from wear, though susceptible to drought dormancy.
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco and Algeria; highly adapted to North America.
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense, tight sod.
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate shade tolerance; requires regular watering to prevent dormancy; thrives in well-drained soil with pH 6.0-7.0.
Mowing & Maintenance
Ideal height 2.5–3.5 inches; requires high nitrogen fertilization (3-5 lbs N per 1000 sq ft per year); high maintenance including dethatching and core aeration.
Special Characteristics
Self-repairing through rhizomes; high wear tolerance for foot traffic; prone to Summer Patch and Necrotic Ring Spot; excellent winter hardiness.
Ecological Information
Introduced/Naturalized status; provides forage for various birds and insects; excellent for landscape soil stabilization; often blended with Perennial Ryegrass or Fine Fescue.