Snohomish County Noxious Weed Control Board
County's top 10 invasive weeds
Giant hogweed: The 15-foot plant was once very popular for landscaping. When exposed to sunlight, its sap can cause second-degree burns on human skin. The plant has been contained to 15 private sites in the county. Call the noxious weed control board if you find one. Round-up is effective.