Kentucky Bluegrass

(Updated: Aug. 22, 2022, 11 a.m. By: Mike Vysocka)

Description

Kentucky bluegrass (Poa pratensis) is the second most widely grown cool-season species in North Carolina because it has a dark green color, a medium to fine texture, and, due to its aggressive rhizome system, can recover from stresses. It prefers fertile, well-limed soils and full sun to moderate shade. Kentucky bluegrass is often mixed with other cool-season grasses like tall fescue to enhance the ability of the turfgrass stand to recover from stresses. Kentucky bluegrass is often confused with tall fescue and/or perennial ryegrass. However, Kentucky bluegrass has a boat-shaped leaf tip and distinctive light-colored lines on both sides of the midrib.

Lawn Maintenance, Athletic Field Maintenance and Cultivar Selection

Species Data

  • SEEDHEAD / FLOWER
    • seedhead is an open panicle. spikelets are flattened, with 3-5 seeds each.
  • VERNATION TYPE
    • leaves folded in the bud
  • LIGULE TYPE
    • membranous; very short, collar-like, 0.008 - 0.04 inches (0.2 - 1 mm) long
      Figure 1
  • GROWTH SEASON / LIFE CYCLE
    • cool season turf
  • AURICLE TYPE
    • absent
  • LEAF BLADE TIP SHAPE
    • boat shaped; usually V-shaped, sharply creased below; two distinct, clear lines, one on each side of the midrib
      ​Figure 2, Figure 3
  • LEAF BLADE WIDTH
    • 0.08 - 0.16 inches (2 - 4 mm) wide
  • STOLON PRESENCE
    • absent
  • RHIZOME PRESENCE
    • present
  • COLLAR TYPE
    • slightly divided by midrib, may have fine hair on edge
      Figure 4
  • SHEATH MARGIN
    • closed, but splits with maturity
      Figure 5
close-up of membranous; very short, collar-like Kentucky bluegrass ligule
Figure 1. Kentucky bluegrass ligule.
broad view of Kentucky bluegrass lawn
Figure 2. Kentucky bluegrass.
close-up of Kentucky bluegrass leaf blade tip shape
Figure 3. Kentucky bluegrass leaf blade tip shape.
close-up of Kentucky bluegrass collar type
Figure 4. Kentucky bluegrass collar type.
Kentucky bluegrass sheath margin
Figure 5. Kentucky bluegrass sheath margin.

This Extension publication can also be viewed at: https://content.ces.ncsu.edu/kentucky-bluegrass