Stewardship In Action
Protecting watersheds one neighbor at a time.
Knotweed is an aggressive invasive plant that damages property and destabilizes the riverbank. Friends of the Cedar River Watershed is working in partnership with Seattle Public Utilities, Forterra, and King County Noxious Weed Control program to provide free knotweed control services to landowners who live along the mainstem or major tributaries of the Cedar River through Renton and Maple Valley. Many sites are also eligible for native planting design and installation to ensure a stable riverbank and meet the needs of the property owner.
This aggressive, invasive plant, a tall, clone-forming perennial, can be identified by its whitish upright flowers and hollow, segmented stems that resemble bamboo. Strong and fast-growing, knotweed can break through pavement, foundations, and infiltrate septic systems. In addition to property damage, knotweed forms dense stands that do not allow other plants to grow and crowds out wildlife habitat. Knotweed is listed as a Class B non-designated noxious weed in King County.
Our team offers free assessment and treatment of knotweed infestations for landowners. The usual method for larger stands is controlled spraying of the knotweed or injection of each stem with an aquatically approved herbicide, treating the area over the course of approximately three years.
However, each infestation is unique and we are committed to getting it under control along the Cedar River.
Contact Amy to learn if your property is eligible for treatment.
The best way to keep knotweed under control and ensure that riverbanks get stabilized is to replant the treated area with plants that are good for fish and wildlife. We offer services to replant your treated area with native plants. We also offer a personalized landscape design and replanting. Our goal is to coordinate replanting and landscaping that meets individual needs. Contact Amy to apply.
News and Upcoming EventsMaple Valley Days
What: Good Plant /Bad Plant Mini Workshop Offered Throughout the Fair - Come Visit Our Booth!
When: June 7-9
Where: Lake Wilderness Park
23601 224th Ave SE
Maple Valley, WA 98038
What is Knotweed and How Do I Get Rid of It?
Join King County Noxious Weed Control Program for the first of their annual series of workshops designed to give landowners hands-on experience with controlling knotweed.
What: Knotweed Control Workshop
When: June 22nd ~ 10:00am-1:00pm
Where: Cedar Grange
22531 SE 218th, Maple Valley WA
Events are Free and Open to the Public
Renton River Days
What: Tabling with Kid-Friendly Watershed Model!
When: July 26th ~ 11:00am-6:00pm
Where: Liberty Park 1101 Bronson Way North Renton, WA 98057
Workshops and Events
Stewardship In Action offers workshops each spring, summer, and fall to help landowners achieve success with invasive plant control and management of native plantings. We are also available to provide on-the-ground support for those who prefer to treat knotweed on their own. Working neighbor to neighbor, we can rid the lower Cedar River basin of invasive plants and restore a healthy ecosystem while maintaining individual property values.
River Resource Buckets
River Resource Buckets are available for participating households!
Our goal is to support the community and the river by providing helpful resources, products, and tools from local businesses.
The River Resource Bucket includes!
- 2 gallon compost bucket from Cedar Grove Compost
- Coupon for two free bags of Cedar Grove Compost
- Soap from Ballard Organic Soaps
- Plant starts from area nurseries
- Renton Curve Card
- Seasonal shopping guide from the Maple Valley Farmers Market
- Friends of the Cedar River Watershed native plant identification cards
- The annual Watershed Report video, featuring students from Tahoma High
- ...and More!
Contact us to learn how your product or service can be featured in the bucket!
2011 Knotweed Treatment Map
Map courtesy of King County Noxious Weed Control Program . Larger version >