LINCOLN SOIL AND WATER CONSERVATION DISTRICT
  • Get Involved
  • Resources
  • District Programs and Services
    • District Programs and Services Overview
    • ODA Mid Coast Agricultural Water Quality Management
    • Watershed Restoration, Enhancement, and Assessment Overview >
      • Conservation Enhancement
    • Noxious Weed Control & Prevention Overview >
      • Invasive Species FAQ
      • Invasive Knotweeds
      • Old Man's Beard
      • Yellow Flag Iris
      • Policeman's Helmet
      • Slender False Brome
      • Yellow Archangel
    • Monitoring Programs Overview* >
      • Fish Surveying and Aquatic Habitat Asessment
      • Water Quality Monitoring
    • Siletz Basin Focus Area
    • Upper Yaquina Strategic Implementation Area
  • Who We Are
  • Native Plant Sale
  • Contact Us

Himalayan Knotweed
Polygonum polystachum

Physical Description
Himalayan knotweed has several distinct identifying characteristics that help with distinguishing it from other knotweeds. The leaves are much narrower than those of Japanese and giant knotweed and have long pointed tips. The clumping growth habit and comparatively narrow stems cause Himalayan knotweed to form very dense patches that are quite difficult to travel through.

  • 5-12 inch lanceolate or spear shaped leaf with a pointed tip
  • 4-8 feet tall
  • Thin, light green, segmented stems
  • Green to red colored papery sheaths between stem segments
  • High density of stems
  • Narrowly hollow stems
  • Cream colored, sweet smelling, flower bunches seen mostly at top of stems
Where is it located in Lincoln County?
Himalayan knotweed infestations in Lincoln County are centralized in the urban riparian corridors of Lincoln City and Yachats. 

Control Efforts
Himalayan knotweed infestations take several years of treatment to control and the most effective method is repeated herbicide application. Contacting a natural resource professional as early as possible is integral to knotweed control. If you see Himalayan knotweed, contact the Oregon Invasives Hotline as well as Lincoln SWCD by phone at (541-265-2653) or email.

Click the link below for an in-depth summary of current knotweed control practices:
Knotweed Control Methods

Our Services

Watershed Restoration and Enhancement
Noxious Weed Control & Prevention
Water Quality & Fish and Habitat Survey Monitoring


Our District

District Staff
District Board of Directors
District History
About Lincoln SWCD

Support

Contact Us
Picture
We've moved!
​914 SW Coast Hwy
​Newport, OR 97365

Mailing address:
Lincoln SWCD
PO Box 2273
Newport, OR 97365

​



Phone: (541) 265-2631​
Email: info@lincolnswcd.org

Office Hours: M-F 8:00 - 4:00*

​*Unless in the field. Please reach out to arrange an office visit so that we can ensure in-person availability.
  • Get Involved
  • Resources
  • District Programs and Services
    • District Programs and Services Overview
    • ODA Mid Coast Agricultural Water Quality Management
    • Watershed Restoration, Enhancement, and Assessment Overview >
      • Conservation Enhancement
    • Noxious Weed Control & Prevention Overview >
      • Invasive Species FAQ
      • Invasive Knotweeds
      • Old Man's Beard
      • Yellow Flag Iris
      • Policeman's Helmet
      • Slender False Brome
      • Yellow Archangel
    • Monitoring Programs Overview* >
      • Fish Surveying and Aquatic Habitat Asessment
      • Water Quality Monitoring
    • Siletz Basin Focus Area
    • Upper Yaquina Strategic Implementation Area
  • Who We Are
  • Native Plant Sale
  • Contact Us