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Oregon Noxious Weeds

​​​The Oregon State Weed Board (OSWB) updates the State Noxious Weed List annually and changes can include the following:

  • Adding new species
  • Changing classification of a previously listed species (A, B, or T)
  • Delisting a species that has become a lower priority​

Noxious weed listing procedure

  • Plant species are submitted for review. Anyone can ask ODA to evaluate a species for listing.
  • An internal review process is conducted to determine if a plant warrants additional evaluation.
  • Plants of high concern, causing documented impacts, are placed on the watch list for further review and research.
  • Formal written risk assessments are prepared.
  • Plants that score high on the risk assessment are presented to the OSWB for listing. Species that score low are kept on file for future reference or may be returned to the watch list.
  • Statewide management plans are developed for A and T listed weeds. Plans for B listed weeds are made, as needed, based on regional priorities and biological control targets.
  • New listed weeds are added to the State Noxious Weed Quarantine (OAR 603-052-1200).​


OAR 603-052-1200: Oregon noxious weed quarantine

OAR 603-052-1200: Oregon noxious weed quarantine

Oregon Noxious Weed Policy and Classification

'A', 'B,' and 'T,' listed weeds for the state of Oregon. The State Noxious Weed List is used to prioritize activities at the state level and provide direction in the development of county weed lists that guide local control programs. This list is part of a Noxious Weed Policy and Classification System and is jointly maintained by the Oregon State Weed Board and the Noxious Weed Control Program. Oregon Noxious Weed Policy and Classification



Main Office
Noxious Weed Control
635 Capitol St. NE
Salem, OR 97301
Phone: 503-986-4621
Fax: 503-986-4786