Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common-type or early-generation cultivar (e.g., 'Kenblue' or 'Baron' lineage)
Hardiness Zones
USDA Zones 2-7; excellent cold tolerance; poor heat tolerance in the Deep South; becomes dormant in winter and summer extremes.
About This Grass
A medium-textured, cool-season grass known for its boat-shaped leaf tips and dark green color. It exhibits a uniform density when well-maintained and enters dormancy during extreme heat or drought, turning tan/brown as seen in the provided image.
Blade Characteristics
Width: 2-4mm (medium); Shape: Flat or slightly folded; Tip: Distinctive boat-shaped (keeled); Color: Dark green to blue-green; Vernation: Folded in the bud; Ligule: Short, membranous, and truncated; Auricles: Absent; Collar: Narrow to medium width.
Root System
Moderately deep fibrous root system with extensive rhizomes that allow for self-repair and high sod strength; tends to form moderate thatch over time.
Growing Information
Origin Region
Native to Europe, North Asia, and the mountains of Algeria and Morocco; naturalized throughout North America
Growth Habit
Rhizomatous (spreading underground), forming a dense, uniform sod with a vertical growth habit
Sunlight & Water Needs
Full sun preferred (6+ hours); moderate to high water requirements; exhibits good drought avoidance through dormancy but poor drought resistance if soil is sandy.
Mowing & Maintenance
Ideal height 2.5–3.5 inches; frequent mowing required during peak spring/fall growth; 2-4 lbs N per 1000 sq ft annually; high maintenance level.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes; highly susceptible to Necrotic Ring Spot and Summer Patch; poor shade tolerance compared to fescues.
Ecological Information
Introduced and naturalized in North America; provides forage for livestock and wildlife; excellent at preventing soil erosion due to dense sod formation; often mixed with Perennial Ryegrass or Fine Fescue.