Collect invasive ivy samples for science!

Got ivy? The Washington State Noxious Weed Control Board wants some! Or, rather, they would like to get samples from ivy populations that are growing wild in Washington. To help figure out which varieties of ivy are escaping cultivation and causing us all such nightmares, send in samples before December 15, 2017. They are conducting this citizen-science study to determine if Atlantic ivy (Hedera hibernica) or English ivy (Hedera helix) is the bigger problem species, or both. Information from the study will help the state decide whether one or both species should be added to the quarantine list.

Invasive ivy growing up a tree and covering the ground in Ravenna Park in Seattle, Washington.

Instructions on how to participate in the study and more background information are on this webpage:

Ivy samples can be collected from your own property or from some public properties. If you plan to collect from public parks or state DNR land, please stay on the trails and do not disturb any other vegetation. Washington State Parks is on board with the study and has issued us a permit that you can download to collect invasive ivy samples. Many county and city parks are also supportive of this project. Please visit the project webpage to learn more and to find out if your local park has any additional requests for collecting ivy samples.

People are being asked to collect one or two vegetative stem cuttings of invasive ivy, provide some basic sampling information, and mail them in. They will identify them down to species whenever possible and will send a subsample off for genetic testing to create herbarium specimens.

Need more information? Email the WA State Weed Board at for more information on English ivy identification, impacts and control, see King County’s English ivy webpage.

Invasive ivy surrounding one surviving native trillium. Who knows what other native wildflowers would be here if they ivy hadn’t taken over.