Take back parks from invasive plant species!
Invasive plants are a serious problem in our local parks and are top of mind for Park Pride volunteer staff, our government partners, and Friends of the Park groups.
Invasive plant species are not native to the local ecosystem and harm the environment. These plants—including English ivy, privet, and kudzu—take over parkland otherwise available for recreation, reduce biodiversity, contribute to loss of habitat for native wildlife, kill trees and reduce canopy coverage, and contribute to soil erosion.
Not only are these species detrimental to the environment and the spaces we enjoy, but in some cases they can even make life uncomfortable for humans. English ivy, for example, provides a perfect breeding ground for mosquitoes!
Invasive species management is difficult, but not impossible, and action must be taken to prevent further spread into parks and damage to the environment caused by these aggressive plants:
English ivy is especially threatening to trees, often contributing to wind damage and rot.
To remove, the ivy can be pulled up from the ground directly, but you should concentrate on the vines climbing up tree trunks. Vines should be cut at a consistent height all the way around the tree with loppers, hand pruners, or pruning saws. They can then be peeled away from the trunk and cleared from around the base tree, creating a 2-3 ft barrier. Be careful to pull the vine gentle from the tree trunk so as not to damage the protective bark. No need to pull vines from tree branches! Once completely disconnected from the roots, the remaining vine will die and fall away from the tree.
Beware: English ivy is often sold in stores as a ground cover—do not purchase and plant in your yard! Invasive species planted in private gardens often “escape” cultivation and end up taking over our parks and greenspaces.
Privet outcompetes many native plants, destroying habitats that wildlife depend on for food and shelter.
Most privet must be managed by digging up the main root structure. Smaller plants can be pulled by hand, particularly in moist soil. Larger plants should be dug up with a shovel, cutter mattock, and/or privet puller.
Do not pull or dig up privet growing within 25 feet of a waterway, or the riparian zone. A riparian zone is the area of vegetation running alongside a waterway and serves as a buffer to pollutants entering the waterway from runoff, controls erosion, and provides habitat. Woody invasives within this zone should be cut at or near the base of the plant. Monitor stumps for regrowth and continue to cut back as needed. Select herbicides can be used in the riparian buffer only by certified professionals.
Beware: Privet is often sold in stores as hedging—do not purchase and plant in your yard!
Kudzu can grow 17-18 inches a day, and often covers (and smothers!) trees and understory plants and bushes in what looks like a blanket of green.
Kudzu is best controlled chemically by qualified professionals; however, it can also be mechanically removed with monthly mowing during the growing season or by manually digging out the nodes or “crowns” from which runner vines grow. Amateur kudzu management should be focused on cutting vines away from trees and shrubs to prevent over-shading. No need to pull vines from tree branches! Simply cut them at a reasonable height to disconnect them from the roots, and the rest will die and fall away from the tree. Kudzu grows quickly, so consistent trimming is key.
The U.S. Forest Service has published a number of integral and free resources to learn more about controlling invasive species you can adapt for use in your park or your neighborhood: fs.fed.us/invasivespecies/.
Other cities have attempted to tackle this problem, focusing on conserving the forest through education, policy, and cross-sector partnerships that highlight everyone’s role in managing the impact of invasive species in public spaces. While the specific plants and ecosystems are different, you can read more about the goals and frameworks set forth by Seattle and Portland through the links below.
- Green Seattle Partnership Strategic Plan
- Portland Citywide Invasive Plant Management and Natural Areas Restoration
Additionally, Park Pride is ready to share what we’ve learned over the years from pushing back invasive species in greenspaces, and we are available to help you create an action plan for their removal and management (and subsequent habitat restoration) in your local park. Working together, we can begin to take back our parks and greenspaces from these invasive plants!
To schedule a consultation, send us an email at [email protected]
P.S. We would like to recognize Corliss Claire as “a lone voice in the wilderness” and a great resource on invasives and invasive management issues. Corliss has played an important role in supporting Friends of the Park efforts at Adams Park, Cascade Nature Preserve and has been active and vocal participant in the Urban Ecology Framework process. Thank you, Corliss, for your leadership and your efforts to educate communities, government and nonprofits on the importance of invasive management efforts.