Noxious, invasive weeds can choke our streams and lakes and make it hard for fish, birds and wildlife to find food and shelter. Salmon have a difficult time going upstream to spawn when the stream is blocked by noxious weeds. Some weeds are poisonous and can cause rashes, illness or death in livestock or humans. Invasions of weeds have the potential to cause increased erosion and fire hazards, and reductions in recreational opportunities and land values. Managing weeds in aquatic environments such as lakes, streams and marine shorelines present unique challenges. The publications below are presented through WSU Extension. Please contact your county’s weed control board for a list of controlled species, specific weeds issues, and methods recommended for weed control in your area.
Send your weed or plant identification requests to the Weed Identification webpage. Specimens may be submitted as digital images or as physical specimens at no charge by following instructions on this site.
General Weed Information
- Video – Noxious Weeds: Everyone’s Enemy – A 50-minute video about noxious weeds.
- Invasive Weeds of Eastern Washington – a 52-page document covering dozens of noxious weeds with the goal of to aiding in the identification and control of invasive weeds found in eastern Washington. Color photos and full descriptions of dozens of weed.
- Aquatic Vegetation Management and Control – A 26-page overview of aquatic vegetation, the importance of water plants; when and how to control vegetation in the water to avoid pollution and harm to other aquatic life. Includes a detailed glossary.
- Aquatic and Riparian Weeds of the West – A guide to the identification and biology of aquatic weeds in the western United States. A 442 page book available for sale.
- Aquatic Pest Control – A booklet covering the management of aquatic pests, effects of pesticides and regulations. Used in pesticide training for Washington State Department of Agriculture licensing exams. Available for sale.
Specific Aquatic Weeds
- Butterfly Bush – Buddleja davidii Franch – Butterfly bush is a garden plant that is now invading and harming streams in Washington.
- Knotweed Shrubs: Identification, Biology, and Management – Fact sheet covering various species of knotweed which invade stream banks causing serious problems.
- Nightshade: Biology and Control in the Pacific Northwest – Fact sheet on how to identify and control of these poisonous plants, many of which grow in moist areas.
- Ornamental Grass Threatens Native Biodiversity – Fact sheet on invasive grasses, highlighting the problems caused by reed canary grass and ribbon grass, which are still available in some nurseries.
- Western Waterhemlock in the Pacific Northwest – Fact sheet on issues and control of poisonous Western waterhemlock with an excellent photographic comparison of similar plants.