Garden Variety: Should you remove vines from trees?
English ivy, Virginia creeper and other perennial vines are sometimes found growing up the trunks of trees in landscapes and wooded areas. They are more obvious in winter months than other times of year because of the lack of greenery on affected trees. Most experts recommend removing vines that grow on tree trunks, but some tree owners like the look, and removing the vines is labor intensive.
Are vines on trees really causing any harm? Like so many other things, the answer depends on multiple factors.
One of the first things to consider is the species of vine and the species of tree. Vines that grow aggressively pose greater risk than native plants with moderate growth. Tree species that are known to have weak structures or be prone to internal decay could be at risk when vines grow on them, because the vines could hide structural damage and contribute to the tree’s failure.
Trees could also be at higher risk if they are young; recently transplanted; growing in a suboptimal environment; already stressed; or if they have internal decay. Expectations also vary with trees in formal landscapes, yards, parks, natural areas and other sites.
Several vines found in Kansas can grow large enough to potentially be problematic: Boston ivy, English ivy, euonymus, kudzu, poison ivy, trumpet vine, Virginia creeper, wild cucumber and wild grape vine. There are many other cultivated and wild species of vines that grow in Kansas, but they are generally not large or aggressive enough to be an issue.
The first three on the list are commonly planted landscape plants. Euonymus grows in different forms and is more of a shrub or groundcover than a vine, but it will stretch up trees sometimes. Kudzu is rare in Kansas but is known to occur. The rest of the species are native or naturalized in Kansas and have varying concerns.
For poison ivy and kudzu, control is warranted when and where possible. Poison ivy is a human health concern. Kudzu is a very aggressive vining plant that can completely cover other plants and block the light they need to survive. Both are easier to control when first found than after years of growth.
There are several reasons experts suggest removing vines from trees. When vines have abundant growth on the trunk or branches of a tree, they can trap moisture against the bark, which contributes to disease. Vines can also hide potential structural problems; cause branches or the entire tree to fail because of their weight; and reduce photosynthesis if the vines outgrow the tree’s leaves and branches.
English ivy, Boston ivy, wild cucumber and wild grape vines produce enough growth that they might cause some of those problems. How much of a problem they cause depends on the size of the vines in relation to the tree they are growing on, the species and the environment.
Gardeners who wish to remove vines from trees because of the potential risks should do so carefully to avoid damaging the tree in the process. Use pruners or loppers to clip the vine’s stems near the ground and sever them from their roots. Pull or gently dig roots out of the ground while avoiding damage to the tree’s root system. Small vines can be easily removed from the trunk by gently pulling, but it might be a better idea to leave larger vines on the tree and allow them to die off before removing them. This reduces damage to the tree’s bark.
How do vines and trees end up entangled? In landscapes, vining plants may be planted as a ground cover or to cover another structure, and they might then grow up a nearby tree as well. In natural areas, vines grow on trees because it is their nature.
Some gardeners like the look of vines on their trees. Before you decide to leave vines as is, it’s a good idea to evaluate whether leaving them in place poses a risk. You might want to consult an arborist or landscaper for additional insight.