The Pacific Northwest region includes Oregon, Washington, and Idaho. With more than 4,430 miles of shoreline, over 19 national forests, and the vast Cascade Mountain Range, this region has diverse topography, abundant natural resources, and varying climates.
The land west of the Cascade Mountains has mild year-round temperatures, wet winters, and dry summers. East of the mountains, it is typically sunnier and drier throughout the year, with colder and much hotter summers.
The Pacific Northwest is one of the most ecologically intact regions in the contiguous United States. Once dominated by the timber industry, the region has shifted away from logging. More than 15 mills have closed in the past decade.
Aquatic invasive species can harm local water supplies, damage native ecosystems, impact outdoor recreation activities, and threaten our health and safety. They cost the U.S. billions of dollars annually to manage and can cause long-term economic and environmental harm.
Common invasive plants in the Pacific Northwest
Some of the most common invasive plants on the Pacific Northwest coast are the knotweed, Spartina, hogweed, Hydrilla and Eurasian watermilfoil, saltcedar or Tamarix spp., Scotch broom, gorse, Himalayan and cutleaf blackberry, English holly, English ivy, butterfly bush, knotweed, thistles, purple loosestrife, common reed (Phragmites australis), Brazilian pepper, purple loosestrife, and Japanese stilt grass.
Invasive species and noxious weed classifications are very regionally specific. Sometimes, a plant classified as invasive in one area may not be invasive in another. Check the local noxious weed lists for species considered invasive and what level of control is required. Treatment/removal is unique to the plant species. Some species are easy to remove with hand pulling. Some species infestations are made worse by hand-pulling and must be controlled with pesticides in accordance with a permit. Consultation with local invasive species authorities is necessary when working with invasive species.
For questions on noxious and invasive plants in your region, the following contacts are a good place to start:
Aquatic Nuisance Species Task Force Directory of Experts – search the database by state to find the contact information for experts in your area.
Oregon Department of Fish and Wildlife:
Oregon Department of Agriculture:
Invasive Species of Idaho:
Washington Invasive Species Council
The best way for you to help prevent the spread of invasive plant species is to stop new outbreaks before they start. Each of us has a role in keeping our waterways clean and healthy for future generations. The best way that you can help to prevent the spread of aquatic invasive species is to always clean your boat after use.
Early detection and reporting can help avoid many of the environmental and economic losses caused by invasive species. Reporting invasive plant species to the experts could stop the next invasion.
Early Detection and Distribution Mapping System (national):
Report invasive plant species in your region:
1-866-INVADER (toll free) more info online: oregoninvasiveshotline.org
Idaho Invasive Species Hotline at 1-877-336-8676
Smartphone Reporting App