“But it looks so pretty!” This is a standard response when I suggest to a landowner that they should remove an invasive species. Whether it’s the flowers or the fruit of a Bush Honeysuckle, or the foliage of a Burning Bush, there is always an endearing aspect to an otherwise harmful species that prevents otherwise well intentioned land stewards from taking action.
This is never truer than with two common species of invasive vines, Winter Creeper (Euonymous fortunei) and English Ivy (Hedera helix). These shade-tolerant ground covers are ever-present, thriving in urban, suburban and rural landscapes alike.
The problem with these species is that they never stay put. Whether it’s up the side of a home, into the garden, out into the forest, or scaling up a tree, Winter Creeper and English Ivy are always on the move. They are resilient as well. Any homeowner who has had the misfortune of needing to remove Ivy from a brick home will attest to the tenacity of these species. Their foliage is resistant to many herbicides, and digging them up only seems to hasten their spread.
The real threat from these species is the damage they can cause to trees. These vines will ascend to the canopy of a mature tree in just a few short years, slowly strangling and smothering its host. The vines extend outward onto the branches of the tree, breaking them and preventing leaves from growing. Without leaves, the tree cannot photosynthesize, and thus becomes weak and eventually dies.
Here’s an experiment: The next time a wind or ice storm comes through town, observe which trees succumb to the elements. I predict that you’ll see a disproportionate number of fallen trees covered in English Ivy or Winter Creeper.
I’ve seen Oak trees five feet in diameter bested by a three inch vine of Winter Creeper which had completely colonized it’s canopy. All it took was some serious wind gusts to instantly destroy a 100-year-old giant. The combination of smothering and the added weight of the vine are often too much for even mature trees to handle.
The good news is that the solution is a relatively simple one. The vines can easily be severed with a small handsaw or hatchet. A small amount of herbicide applied to the cut surface of the vine will keep them from regrowing, or one could simply continue to sever the vines year after year. The important thing is to keep the invaders out of the canopy of the tree.
There are several species of beautiful native, non-invasive vines that do not kill mature trees, but rather grow in symbiosis with them. Although they are a much better choice for the home landscape, even native vines can overwhelm smaller trees and shrubs. This can be avoided with regular pruning, as well as selecting an area where the vines will not be in competition with existing vegetation. Here are a few that I recommend:
Virginia creeper (Parthenosisis quinquifolia) – This common native plant can be used as a climbing vine or ground cover, with abundant green leaves that turn brilliant colors in the fall. Its tendrils end in adhesive-like tips instead of penetrating rootlets, which don’t damage buildings the way some vines do.
Dutchman’s pipe (Aristolochia macrophylla) – The unique green and brown flowers of this Eastern American native superficially resemble a pipe. The lush green foliage of this plant really stands out on a trellis or arbor.
Trumpet honeysuckle (Lonicera sempervirens) – A beautiful native member of the honeysuckle family, with showy, red and yellow trumpet-shaped red flowers blooming in the Spring.
Crossvine (Bignonia capreolata) – A climbing, woody vine reaching 50 feet long with spectacular clusters of orange and red trumpet-shaped flowers.
American Bittersweet (Celastrus scandens) – A high-climbing woody vine, reaching 30 feet, distinguished by it’s showy orange fruit. Not to be confused with Oriental bittersweet, which has escaped cultivation and can be a problematic invader.
Several of these species can be seen growing in the Marshall Playground and Sprayground in Beckley Creek Park. I’m certain that one look at the lush foliage and beautiful flowers of these vines will have you convinced to eliminate the invasives and plant beneficial natives.
About the Author
Andrew joined the 21st Century Parks team in 2012 as the Natural Areas Team Leader, responsible for the restoration and maintenance of the woodlands, meadows and trail system within the park and worked on The Parklands project until February 2015. Previously Andrew worked for Louisville Olmsted Parks Conservancy, NativeScapes, Inc., and the National Park Service, at both Rocky Mountain National Park and Point Reyes National Seashore. He graduated from the University of Kentucky with a degree in Geography.