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  • Writer's picturekristi park

(Not) Down with English ivy.

Updated: Apr 27, 2023

How you can help petition to add English Ivy to the WSDA Prohibited Plants and Seeds list!

We feel sheepish to admit that until last Friday, we didn't realize that Hedera helix is being sold commercially in local nurseries in Washington State. Thank you to @ for sharing your knowledge with us!

Anyone who is reading this blog post is likely already aware that English ivy (Hedera helix) is an aggressive non-native invasive plant that can destroy a forest (both the canopy and the understory) in a matter of years. If trees do manage to survive the entangled grasp of Hedera helix, the diversity of plants under the tree is often nearly completely destroyed.

Thousands of hours of volunteer and hired labor are spent trying to remove ivy from urban and suburban forests, yet despite significant efforts to remove this plant, English ivy can legally be sold and planted! What a waste of everyone's time! Mind-blowing!

By April 30th, 2023 (a potential cut-off date to have this plant discussed in 2023) we will be filing a request to and to ask that four cultivars of Hedera are added to the WSDA Prohibited Plants and Seeds list. Although it would be beneficial to add additional cultivars of Hedera helix to the list, a minimum request includes the addition of the following Hedera cultivars including: Hedera helix 'Baltica', 'Pittsburgh', and 'Star'; Hedera hibernica 'Hibernica' which are already listed as Washington Class C Noxious weeds.

TAKE ACTION against English Ivy! Would you like to file a petition as well? Simply email and requesting that Hedera helix (specifically the four cultivars already listed as Class C noxious weeds): Hedera helix 'Baltica', 'Pittsburgh', and 'Star'; Hedera hibernica 'Hibernica') are added to the WSDA Prohibited Plants and Seeds List.

Include the following information in your email. Want to cut/paste a template of answers - please feel free to modify as you see fit! Link here:
Request to Add Hedera helix to WSDA Prohibited List
Download DOCX • 1.06MB

Required Elements in the request:

  • The common and scientific name of the plant species, if known

  • The specific change request (addition, removal, class or designation change)

  • The reason why you are requesting the change

  • Whether there have been any attempts to control the plant

Additional information that may be included but is not necessary:

  • Any plant samples, pictures, and any literature about the plant are useful.

If you would like to learn more about this process, we included a downloadable link to WA Chapter16-750 WAC:
WA State_Chapter 16-750 WAC Noxious Weed List
Download PDF • 122KB
This is the first step to add English ivy to the Prohibited Plant sales list...

Although this request seems like a no-brainer, several County noxious weed organizations were generous to share their experience with petitioning WSDA to add English ivy to the list and as it turns out, there is a complicated backstory to this process.

The abridged version of the story, there are folks out there who lobby on behalf of the plant-growing industry to keep Hedera helix cultivars off the list and so far, they are winning. Game on lobbyists – game on!

More about English ivy:

Did you know? From data collected by the Whatcom Million Trees Project:
"Between 2005-2011, the City of Seattle has spent more than $8 million of public funds (plus $3 million from private sources) on English ivy and invasive removal in parks through the Green Seattle Partnership effort to maintain healthy urban forests. Add 400,000 volunteer hours donated by Seattle residents during the same time period, and you get an idea of what English ivy has already cost us."

Per King CountyEnglish ivy and its close cousin Atlantic or Irish ivy are well-known European vines that have been widely used in North America landscapes. Because this type of vine is evergreen and well-adapted to the mild Pacific Northwest climate, it grows all year round in western Washington and can out-compete many other plant species. This aggressively spreading vine can cover everything in its reach and has no natural checks and balances to keep it under control.

In the understory of forests, English ivy spreads over the ground and crowds out native wildflowers, ferns and tree seedlings. Ivy mats often host pest animals such as the Norway rat. Also, because ivy roots are shallow, thick mats covering hillsides can increase problems with slope failure as water runs down under the ivy and entire mats of ivy and soil slide downhill. On walls and fences, ivy rootlets work into the wood and mortar and can cause structural and aesthetic damage.

When English ivy is allowed to grow up tree trunks it can increase the risk of the trees being blown over in windstorms because of its large mass and “sail effect” of the vines in the canopy. Tree bark is more likely to have disease and rot problems and the tree health can be damaged by reduced access to light when the vines cover the tree’s branches. Although ivy won’t directly poison the tree, it will most likely harm the tree’s health and increase the chance of it becoming a hazard tree.”

Additional resources per King County's website:

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