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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

More Contact Info

How can folks help?

giant hogweedControl where it goes

Prevent these plants from going to seed by managing them early, and avoid swapping new starts.

Control where it grows

  • Dig: Digging up hogweed is effective, but the risk of injury from exposure to sap is substantial. Flowerheads are also clipped off mature plants, bagged and put in the garbage. Landowners who attempt to remove hogweed themselves should dress appropriately, though relying on professionals to do the removal is recommended. Landowners who remove hogweed personally are also still REQUIRED to notify the Oregon Department of Agriculture of its presence, for tracking and surveying purposes.
  • Treat: On patches of more than a few plants, herbicides are used in combination with the manual methods described above.
  • Check: monitor the site at least annually, and especially years two and three after treatment, as any surviving seed takes its big opportunity to sprout!

Last words

If you suspect you’ve found giant hogweed, the Oregon Department of Agriculture, and the City of Portland both REQUIRE you to report it.  You can report suspected patches to:

  • the Oregon Department of Agriculture at 1-866-INVADER (1-866-468-2337), or;
  • Mitch Bixby with the Environmental Services' Early Detection/Rapid Response Program at 503-823-2989 or

Both the Oregon Department of Agriculture and the City of Portland offer assistance with managing giant hogweed if you would like it.