By Jennifer Leach, Environmental Education & Sustainability Coordinator ~ Parks, Recreation and Cultural Services
If you’ve been out in Edmonds’ forests or green spaces lately, chances are you’ve noticed patches of dense green vines that carpet the ground and climb high into the trees in some places. That’s English ivy, and it’s threatening trees and forests all over our City.
This fast-growing evergreen vine is listed as a noxious weed throughout Washington State. Even so, it continues to be widely sold at plant nurseries and is an extremely popular groundcover. Vines grow rapidly along the ground up to 15 feet in a year. Once they start growing vertically (i.e. on trees, fences), the plants will produce berries which are eaten by birds and carried deep into our forests and green spaces. Once established, ivy can wreak havoc in a forest. Dense clusters of vines can add hundreds of pounds of weight to a tree, increasing the potential for broken limbs or uprooting of the whole tree as it becomes more susceptible to wind throw. On the ground, ivy forms a dense mat that prevents other plants and trees from growing, destroying habitat for other forest species and leading to a phenomenon often referred to as an ‘ivy desert’.
Edmonds residents can do a lot to prevent the spread of English ivy. The easiest way to ensure that ivy doesn’t get into our forests is to avoid planting it on your property. There are lots of great groundcovers for sale that aren’t considered pests - ask your nursery professional to recommend a few that are right for the conditions you have in your yard. If you already have ivy, consider replacing it with a suitable alternative or manage it responsibly by keeping it off your fences and trees where it will produce seeds and disperses into the forest.
Pulling ivy out by the roots is the best way to remove ivy that hasn’t started to climb, and winter is the best time to do it. In winter, ivy’s waxy evergreen vines are easy to spot once deciduous foliage has died back. Roots can be pulled out easily when the ground is wet and soft. For large infestations, try rolling ivy up and back like a carpet. Ivy vines can re-sprout, so be sure to dispose of the pulled plants off site or put a tarp down if you plan to leave them to dry out and/or compost on site. If you’re not planning to replant the area right away, a couple of inches of bark mulch will prevent soil erosion and keep other weeds from sprouting up.
To remove ivy growing on a tree, simply cut the vines all the way around the tree at both ankle and shoulder height and remove the section between the cuts. Peel back the ivy at the base cut at least six feet away from all sides of the base of the tree to keep it from climbing back up the trunk; vines above the cuts will dry out and fall off on their own. Never use pesticides on ivy as the chemicals can damage desirable plants in the area, poison the soil, and get into local waterbodies through stormwater runoff.
In celebration of Earth Day 2017, the Edmonds Parks Department will host an ivy removal event at Hutt Park on Saturday April 22, where ivy has taken root throughout the park. We’ll kick off the event with a tour of the park by a Discovery Programs naturalist to see what makes this forest so unique. Hint: Hutt Park is one of the last remaining patches of old growth forest in our area. To learn more, contact Jennifer.email@example.com or call 425-771-0227.
For more tips on how to remove English ivy, check out this article from the King County’s Noxious Weed News. https://kingcountyweeds.com/2017/01/06/english-ivy-january-2017-weed-of-the-month/