Integrated Pest Management

Prostrate Knotweed

Polygonum aviculare

prostrate knotweed

Prostrate knotweed growth habit (Robert Videki, Bugwood.org)

prostrate knotweed

Prostrate knotweed flower (Bruce Ackley, The Ohio State University, Bugwood.org)

 

Description

  • low-growing plant with wiry stems that radiate out from a central point and grow up to 2 feet in length
  • small leaves join the stems at enlarged “joints” that are covered in a papery sheath
  • tiny white or pink flowers have five petals and green centers

Location

  • commonly grows in planting beds but can sometimes be found in lawn areas

Life Cycle

  • summer annual with seedling germination in early spring; seedling growth is slow
  • flowers and seeds are produced mid-spring to fall frost

IPM Recommendations

  • Hand-pull plants prior to seed maturation.
  • Prostrate knotweed thrives in compacted soil; avoid or reduce soil compaction by aeration or preventative methods.
  • Apply a mulch layer 3 inches deep on planting beds to reduce seed germination.
  • Apply an appropriate pre-emergent herbicide prior to seed germination or post-emergent herbicide to young seedlings (less than 3 inches wide).