Invasive weed Control

Frequently asked questions

why am i seeing this sign?

Hello! You’ve come across our notice of herbicide application signs in your local public spaces, and might have some questions.

This sign is there to let you know that members of our restoration crew have applied a chemical herbicide to the invasive species specified on the sign. The treated plants are located somewhere behind the sign.

So why are we in your neighborhood? We’re trying to get rid of invasive and noxious weeds near rivers and creeks. Noxious weeds threaten current and future salmonid habitat by outcompeting native vegetation, leading to increasing erosion, undercut banks and murky water. The young salmon living in the river or creek need cold, clean, and clear water to thrive!

Several weeks from now, the plants that we’ve treated will be dead, making space for native plant species to establish. In time, this will provide long-term shade to the waterways, cool down the water temperature, produce large woody material that young salmon use to hide from predators, improve soil stability, filter rain and groundwater, and aid in water retention during flood events. These numerous benefits also help improve the water quality of our watersheds, and support both mature and juvenile salmon.

At SSS, we use aquatic formulations for our herbicides. This means that even though we are applying them near water, the herbicides have been formulated in a way that is safe and causes little to no harm to fish and other aquatic species in the area. Additionally, our dedicated restoration crew takes every safety precaution, and strictly adheres to herbicide safety laws and handling protocols. We also take precautions to avoid harming native plants and animals in our treatment areas, using safety shields and avoiding flowers.

Some things to keep in mind to safely enjoy your public spaces when this sign and associated herbicides are present: 

• These signs are here for your safety. Do not enter the regions behind them until the specified time window has ended. While the herbicides are formulated to be water safe, there are still risks when direct exposure is possible, either through direct contact with or ingestion of treated plants. 

• This risk extends to your pets! Please do not let your pets enter recently treated areas, even on a leash. 

If you have any further questions regarding invasive weed control in your area feel free to reach out to our habitat team at 425-252-6686.

Who is Sound Salmon solutions?

Sound Salmon Solutions is a local non-profit Regional Fisheries Enhancement Group (RFEG) that has supported and implemented salmon recovery efforts in the Snohomish, Stillaguamish, and South Island County watersheds for over 30 years. We are committed to the restoration and conservation of salmonid habitat through invasive weed control and native revegetation of under- and overstories, actions that help provide cold, clean, & clear water in the face of a changing climate and rapid urbanization. 

Why are you not controlling the weeds mechanically?

We are! We pull and/or mow invasive weeds whenever feasible. The site you’re looking at was chosen for herbicide use instead because of logistical barriers (the infestation is far too big to pull by hand, or the terrain is too rough to get a machine in) or biological concerns (some noxious weeds are poisonous to humans and present a safety risk, and some respond to pulling and mowing with increased growth and spread; the opposite of what we want!).

Why are noxious weeds detrimental to salmon?

First, we need to understand what a healthy river system looks like. The land on either side of a river or stream is referred to as the “riparian” zone. Over the past century, many riparian areas and adjacent lands have been logged or converted for agricultural purposes or development. Following the removal of trees and shrubs, these areas often become overgrown with invasive weeds, which can grow aggressively and hinder the natural reestablishment of native vegetation. The abundance of noxious weeds and lack of native trees along rivers and streams has contributed to rising water temperatures and reduced soil stability. High water temperatures can be detrimental to adult and juvenile salmon alike, and the input of fine sediment caused by excess bank erosion can also have negative impacts on egg and juvenile survival. By removing invasive weeds and replanting riparian zones with native trees and shrubs, we can achieve reduced water temperatures, stabilized river and streambanks, improved water quality, and numerous other benefits to salmon and other aquatic and terrestrial wildlife.

What is Himalayan Blackberry?

Himalayan Blackberry is a common, invasive, and fruiting shrubby plant known for its dense, thorny stands that tend to outcompete any surrounding vegetation; going as far as to grow on top of itself as it shades itself out. It is most notable by its sheer size when compared to other local blackberry species and its 5 point leaves, creating a pentagon shape. Himalayan Blackberry threatens salmonid habitat by preventing the establishment and sufficient growth of native tree & shrub species, which are important for providing adequate shade to our local water bodies. This leads to murky and warm water, which negatively impacts salmonid species’ ability to navigate and spawn. 

What is KNotweed?

Knotweed is a quick-growing noxious weed in Western Washington State. It grows rapidly starting in spring, and dies away above the soil at the beginning of winter, leaving living roots underground. These roots send out runners, expanding infestations by dozens of square feet per year. It is most notably defined by its oval to triangular leaves that alternate in a distinct zig-zag pattern, its white/green flowers that bloom from early August to late September, and hollow bamboo-like stems. In Snohomish and King counties, there are 4 species present.

How can I help?

Interested in joining us in restoring riparian habitat for salmon by planting native plants and removing invasive species? Restoration events typically take place October - April in conjunction with the planting season. See all upcoming events and register here!

Do you live on a salmon-bearing creek or stream, and are interested in having SSS help restore your riparian buffer? Please reach out to our Program Manager, Matt Distler, at Matt@soundsalmonsolutions.org