Vine or No Vine, That is the Question
by Marcia Woolman
Spending winter days in the surrounding woodlands, or even observing trees in villages and on old estates, brings an awareness of vines growing on far to many trees.
Always looking for an important conservation issue, I was prepared to warn readers of the danger of vines killing your trees. But, I wasn’t sure to what degree this was true, so I set out to read and learn whether vines really do kill trees.
The answer? Yes and no.
For most native vines like Virginia Creep the answer is no. But with invasive English Ivy, for instance, the answer if yes.
If the ivy is thick enough, the damage could be happening at all parts of the tree. English Ivy in the canopy can shade out your trees and slow photosynthesis. The extra weight the vines add can bring down branches and even whole trees, especially if loaded with ice or snow. The really thick vines create micro climates underneath that can cause rot on the trees. Like all weeds, English ivy also competes for light, air, space and nutrition.
Other vines, like oriental bittersweet, can spiral around the tree and choke it. One of the signs of spiral vines is that they leave indentations in the tree itself. I have seen these used to create very interesting walking sticks, but if the tree is to remain on your property you may not want it to be disfigured in this way. If you want to protect your trees, always remove oriental bittersweet and English ivy on sight. Learn to identify it, and be proactive.
If you decide a vine needs to be removed, the best and easiest approach is to cut the vine so anything above the cut dies. Don’t try to rip it out of the tree right away. I have found if you wait a year and let it die and become brittle, it will often come down even from the very top with a series of tugs that break up the vine tendrils rather than rip off leaves or small limbs from the tree. So be patient.
The other method I saw was used on a large native cedar tree right in the front yard of the PEC office building in Warrenton. The vine was cut about shoulder high and again just above the ground. They then proceeded to clear out as much of the vine root structure as possible to keep it from growing back up the tree, leaving the upper vines to die from lack of water.
Some vines don’t seem to do much harm. Virginia Creeper and poison ivy rarely harm trees. Hairy looking vines are a tell-tale sign of poison ivy. If you have to remove them, the best time to do it is in the winter, but you still need to be extremely careful. And NEVER burn poison ivy plants. The oil can be dispersed through the air and that is something that you never want to inhale.
Keep in mind that vines are an important part of our native forests. Vines add a lot of bird habitat along tree trunks and thick tangles. Flowers and fruit are found on many vines, which in turn support a lot of interesting insects that become food for birds.
Many people, including myself, thought that all vines should be removed to create a “healthier” woodland. But removing all of the vines creates a neat looking woodland, but destroys important natural habitat that belongs in our environment.
The earliest European explorers reported thick tangles of vines hanging from trees along the coast and along rivers, and an abundance of wild grapes.
It’s unusual for a native vine to seriously harm a healthy tree. Invasive vines are usually the ones that end up damaging the trees. Rather than trying to kill all of your vines, try to appreciate them for what they are—an important part of the forest.
(Marcia Woolman is a regular columnist for Middleburg Life, and chair of the Goose Creek Challenge, an annual riparian buffer tree planting project using school students to plant donated trees.)