Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 turfgrass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass; also used for Pasture and Erosion Control
Variety / Cultivar
Common or 'Naturalized' Kentucky Bluegrass (likely mixed with weeds)
Hardiness Zones
USDA Zones 2-7. Highly cold tolerant but struggles in the heat of the Deep South. Becomes dormant (brown) in winter in colder climates.
About This Grass
Medium-textured turfgrass with a distinct dark green to blue-green color. It forms a dense carpet when well-maintained but currently appears in a mixed stand with broadleaf weeds (clover and violets). It produces panicle-type seed heads if left unmowed.
Blade Characteristics
Blade width is medium (2-4mm) with a characteristic 'boat-shaped' tip. Vernation is folded in the bud. Leaves are smooth with a dual-line midrib (keel). Ligule is short and membranous; auricles are absent.
Root System
Fibrous and rhizomatous. Rhizomes allow for self-repair and sod formation. Rooting depth is typically moderate (6-12 inches depending on soil conditions). Establishment speed from seed is slow (21-28 days for germination).
Growing Information
Origin Region
Europe, Northern Asia, and Northern Africa; naturalized throughout North America
Growth Habit
Rhizomatous (spreading via underground stems), forming a dense sod over time
Sunlight & Water Needs
Full sun preferred (at least 6 hours). Moderate to high water needs; will enter dormancy during severe drought to survive. Prefers well-drained fertile soil with pH 6.0-7.0.
Mowing & Maintenance
Recommended mowing height: 2.5 to 3.5 inches. Requires regular fertilization (2-4 lbs N/1000 sq ft/year). High maintenance due to water and nutrient demands. Occasional dethatching is necessary.
Special Characteristics
Excellent wear tolerance and recovery due to rhizomes. Good cold hardiness. Susceptible to summer patch, leaf spot, and dollar spot. Low shade tolerance compared to fescues.
Ecological Information
Introduced but naturalized in North America. Provides forage for livestock and wildlife. Its dense sod-forming habit provides excellent soil stabilization and water filtration.