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Remove Invasive Weeds

Invasive Weeds Program

 Multnomah Weed Watchers
 Strategic Partnerships
 Garlic Mustard Information
 McCarthy Creek Project
 Japanese Knotweed Information
 Balch Creek Restoration
 Multnomah Channel Project
 Boones Ferry Project
 Neighborhood Weed Pulls

Invasive weeds significantly impact landowners around West Multnomah County and throughout Oregon. Noxious weeds displace native and desirable plants and wildlife habitat. They also negatively affect timber and agricultural production. For information on invasive weeds contact Invasive Species Program Coordinator Michelle Delepine, 503/238-4775, x 115; michelle (at)

West Multnomah Soil & Water Conservation District (WMSWCD) has a comprehensive plan to deal with this imporatant natural resource issue. The plan uses the following tools:

  • Inventory
  • Assesement
  • Coordination
  • Education & Outreach
    English Ivy strangling trees
  • Control
  • Restoration

Click here to see our Invasive Weed Brochure

The District Invasive Weed Program has four main focus areas that help direct program efforts:

  • Multnomah Weed Watchers/Early Detection and Rapid Response Program (EDRR)
  • Strategic Partnerships
  • Educational Demonstration Projects
  • English Ivy in Forest Park
  • Wildlife Corridor & Declining Habitat Focus

To find out more please see the Invasive Plant Species Strategic Work Plan (5 year plan)


Canopy Weed Removal around Forest Park

In an effort to reduce the spread of invasive vines and save trees surrounding Forest Park West Multnomah Soil & Water Conservation District (SWCD) launched a Canopy Weed Removal program this spring.

This past spring a total of 2,777 trees were freed of canopy weeds, 10 landowners participated and 33 acres were cleared of canopy weeds!

In cooperation with Forest Park Conservancy and Portland Parks & Recreation, West Multnomah SWCD is now offering FREE treatment of invasive canopy weeds on private landowner’s trees to landowners within priority areas around Forest Park, one of Portland’s greatest natural treasures. Invasive vines prevent trees and bushes from getting sunlight, can spur disease and rot and add considerable weight
trees, eventually weakening and killing them.

The weeds WMSWCD is targeting are English ivy (Hedera helix), Atlantic/Irish ivy (Hedera hibernica) and Traveler’s Joy (Clematis vitalba). They are non-native, ggressive European vines that can completely blanket trees and other plants. On the ground, English ivy crowds out native wildflowers, ferns and tree seedlings. Mats
of ivy often become home to pests like the Norway rat. Also, because ivy roots are shallow it does little to stop erosion, heavy rain running underneath the plants can cause an entire mass to of ivy and soil to dislodge and slide downhill. On walls and fences, ivy roots work into the wood and mortar causing structural damage.

To participate in this program landowners must agree to keep invasive vines from climbing back up their newly cleared trees and allow for WMSWCD staff to come back and check the trees occasionally over the next five years to see if the program is successful.

WMSWCD and the Backyard Habitat Certification Program offer additional technical assistance and holistic planning to help participating landowners address all of the conservation issues on their property including other invasive species removal, native plant establishment, stormwater management and wildlife enhancements. 


Multnomah Weed Watchers

Early Detection & Rapid Response (EDRR)

EDRR promotes prevention methods such as cleaning your boots and bike tires to checking the spread of a new garden plant. If prevention isn't possible, the most time and cost-effective way to manage new invasive plants is through EDRR efforts. They include early detection while weed populations are small and rapid control measures, increasing the likelihood that new invasions will not become established.

This program is a county-wide partnership that includes East Multnomah Soil and Water Conservation District and the City of Portland Bureau of Environmental Services (BES). 

Please see our current EDRR Watch List.  For detailed descriptions of the weeds, click here.

To see our Weed Watchers EDRR ID Guide; click on the links below:

Become a Weed Watcher!

The EDRR program can only be successful with your help. The more eyes on the ground, the better chance we have of keeping new invaders out. To become a Multnomah Weed Watcher please attend one of our trainings or contact us to train your group.

Have you spotted an EDRR Invasive Weed? 
Report here any sightings in Multnomah County. To reach the City of Portland EDRR specialist, call Mitch Bixby at 503/823-2989. To contact the East Multnomah SWCD specialist, call Lucas Nipp at 503/935-5363.

In West Multnomah County or on Sauvie Island: REPORT NOW or call Mary Logalbo at 503/238-4775, ext. 103.

Strategic Partnerships

These partnerships help us achieve invasive weed control goals:

West Willamette Restoration Partners

4 County Cooperative Weed Management Area (CWMA)


On-the-Ground Weed Control Efforts

Garlic Mustard Control

WMSWCD seeks to identify and treat invasive garlic mustard in unincorporated west Multnomah County. The City of Portland may be contacted (Mitch Bixby at 503-823-2989) for sightings in west Multnomah County inside city boundaries. 

If you find any patches of garlic mustard on your property or elsewhere, or if you need assistance identifying or treating this invasive weed, please contact Urban Conservationist, Mary Logalbo; mary (at) or 503.238.4775 x103. 

If you know you have Garlic Mustard and would like our help please send in this Permit of Entry and Treatment Form.


Garlic Mustard Information

Invasive species harms hardwoods by killing soil fungus

Plant Conservation Alliance Fact Sheet

Garlic Mustard, Invasion Biology Introduced Summary Project, Columbia University

Images from a google search

Garlic Mustard Cook Book (from Pest to Pesto)

ODA Weed Profile

King County, Washington Garlic Mustard control


McCarthy Creek Knotweed Control Program

McCarthy Creek is one of the worst knotweed infested creeks in our District. WMSWCD was contacted by landowners concerned that this extremely invasive plant will clog the creek and take over riparian forest zones. In response, the District is on its second year of treating knotweed throughout the watershed. The project is possible, in part, due to an Oregon Department of Agriculture/Oregon State Weed Board Grant. WMSWCD is seeking the assistance and cooperation of landowners to help locate patches of Japanese knotweed, and to grant permission for contracted services to treat it in or near McCarthy Creek. For more information about this project, contact Mary Logalbo at 503-238-4775 x103. If you live on McCarthy Creek and would like help from the District please fill out the following Permission to Access and Treat form


Japanese Knotweed Information

Plant Conservation Alliance Fact Sheet

Japanese Knotweed Alliance

Japanese Knotweed identification and recipes

Japanese Knotweed Video

Images from a google search


Balch Creek Restoration Demonstration Project

The Balch Creek Partners (BCP) is a cooperative interagency task force that coordinates conservation efforts to protect and enhance the natural resources of the Balch Creek Watershed. BCP envisions a healthy watershed that is protected and enhanced in a sustainable way, benefiting people, plants and animals. 

The Balch Creek Watershed contains over 120 plant species and over 70 resident and migrant wildlife species, including native Cutthroat Trout. Currently, WMSWCD is working on 10 acres of land with voluntary landowners on a demonstration restoration project in the headwaters of Balch Creek. To find out more or contact us.

Please take a moment to review the Balch Creek Declaration of Cooperation to find out more about the project and our program partners.


Multnomah Channel Habitat Connection

The District has recently started large-scale (over 60 acres) watershed restoration work with landowners in the Miller & Ennis Creek Watersheds. City of Portland studies found native runs of federally listed ESA anadromous salmonid species using Miller Creek for habitat and possibly rearing/breeding grounds. In addition, these interconnected private forestlands, adjacent to public open space managed by the City of Portland and Metro, provide contiguous habitat for a variety of wildlife that use the Tualatin Mountains (West Hills). They include extensive varieties of birds, mammals, and amphibian species.


Boones Ferry Crossing Restoration Project

In the Tryon Creek Watershed, WMSWCD is working with the Tryon Creek Watershed Council and the City of Portland Revegitation Crews on a major invasive species removal and native plant restoration project with a fantastic group of voluntary landowners.


Neighborhood Weed Pulls

WMSWCD provides technical and financial support to neighborhood weed pulls throughout our District. Contact us if you would like some help.


Please visit our Resources page for more information on invasive species from weeds to animals and beyond!

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More Videos

Invasive Holly

Invasive Holly

English holly looks nice but it's an invasive species that will sprout all through your property!  Our Urban Conservationist Mary Logalbo will tell you how to get rid of it in the above video.

More Videos

Invasive Blackberry

Invasive Blackberry Video

Invasive Himalayan or Armenian blackberry can be found throughout the Pacific Northwest and takes a little effort to get rid of!

WMSWCD Urban Conservationist Mary Logalbo shows you the easiest way in this video.

Common Noxious Weeds

Old Man's Beard 
(aka. Clematis)

Dig clematis and pull all vines, including those running along or just under the ground. Roots must be broken off or cut off at least 2-inches under the ground. Vines on trees can be cut with shears at both knee and chest-height to avoid re-growth. Bag cut and pulled pieces to avoid re-sprouting. Expect to dig and cut up to 5+ times before eradicated.


English Ivy

Cut or pull by hand, focusing on tree ivy as first priority. Cut tree ivy at both knee and chest height, and leave to die. Pull back ivy within 6ft of tree base. Ground ivy can be rolled up into "logs" and left in piles to compost. Turn pile occasionally to prevent re-sprouts. Expect to cut and pull more than once.


Garlic Mustard

Pull plant before it goes to seed (around late May), careful to grab at base of plant to remove entire root. Pulled plants must be bagged to prevent re-sprouting, since the plant can continue to germinate seeds after being pulled.


How to Spot Invasive Weeds

  1. Look in "disturbed" areas such as ditches, roadways, pastures, and recently developed areas.
  2. Attend a Multnomah Weed Watchers workshop to learn how to identify and report some of the most troublesome new invasive plants (Early Detection and Rapid Response).



Garlic Mustard Pull


What You Can Do

  1. Know your plants, particularly invasives
  2. Control invasive plants on your property and encourage your neighbors to do so
  3. Avoid disturbing natural areas and dumping invasives in yard waste
  4. Use as many native plants as possible in landscaping
  5. Report invasive plant sightings at








 McCarthy Creek,  Knotweed Infestation










 Learning about Native Plants and Rainwater Catchment,
Balch Creek Watershed Summit


Invasive Species Resources

Native Species Resources