Washington state bans invasive ivy

Washington state has banned the sale or transport of English ivy and its cousin, Atlantic ivy.

The leafy holiday decorations are also aggressive invaders of Northwest forests.

The Washington State Department of Agriculture on Wednesday added 19 species to its quarantine list of plants and seeds that cannot be sold or distributed in the state due to their potential to wreak havoc on agricultural and natural areas.

None of those noxious weed species attracted nearly as much attention as the two European ivies.

“Local jurisdictions and Washington state spend millions of dollars, either in volunteer hours or actual funds, to remove ivy from forests, urban forests in particular,” said landscape architect Kristi Park of Bellingham. “So, the fact that you could turn around and buy it just blew my mind.”

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In 2002, Washington’s Noxious Weed Control Board listed three cultivated varieties of English ivy and one of Atlantic ivy as “Class C noxious weeds,” but that designation carries no restrictions on growing or selling a plant.

Some nurseries, big-box retailers, and online stores continue to sell ivy in Washington state. They have to stop doing so by Aug. 9.

Park called ivy “a forest choker.”

“Not only does it climb up trees and, eventually, suffocate and kill the tree, but it also destroys the understory. And it spreads very quickly, and it's very difficult to get rid of. It can take down a forest in a matter of years,” Park said.

Anyone can petition the Washington State Department of Agriculture to add a species to its list of quarantined plants, currently numbering more than 130 species. Until 2023, no one had ever done so for English ivy.

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Three individuals, including Park, and one nonprofit group, the Whatcom Million Trees Project, each petitioned the agriculture department to add ivy to its quarantine list.

“It really wasn't on my radar that ivy was for sale in big box stores and nurseries, but when I found out that it was, I felt that I needed to do something about it,” Park said.

Agriculture officials said they received hundreds of comments urging a ban on ivy and none opposing one.

Other species newly added to the quarantine list include European Coltsfoot, Russian Knapweed, Turkish thistle, and puncturevine, a low-growing European plant with spiny seed pods that can pierce feet, hooves, and tires.

Washington is the second state to ban ivy. Oregon prohibited the sale of English ivy in 2010.