Help Collect Invasive Ivy Samples


The State Noxious Weed Control Board is seeking the public’s help working on a project to conduct an updated sampling of escaped, invasive ivy in Washington to determine whether Atlantic ivy, Hedera hibernica (commonly called English ivy), is still the more abundant species compared to English ivy, Hedera helix.  A 1999 study (Murai 1999) examined 58 wild ivy populations from southern British Columbia to northern Oregon and determined 83% of them were made up of Atlantic ivy. With this project, our goal is to collect a large number of invasive ivy samples in Washington State to determine at as fine a scale as possible, what ivy species is invasive in the state and where it is growing. Leaf size and shape, along with small hairs on the plant, will be the main traits we use to identify the species of the sample. Some of the samples may be used to make herbarium specimens or used for genetic testing. The information from this study will be used in the effort to propose quarantining one or both ivy species that are found to be invasive in Washington. 

Thank you for your help with this project! We have stopped collecting invasive ivy samples and are currently processing them. Thanks to the generosity of volunteers, we have received over 350 samples from throughout western Washington! Please check back for updates.



Murai, M. 1999. Understanding the invasion of Pacific Northwest forests by English ivy (Hedera spp., Araliaceae). Master’s thesis. University of Washington, Seattle