By Debra Huff
Michigan forests are host to many vines, both native and non-native. Do you know what vines you have in your woods?
Vines are part of the natural forest system and can provide food and habitat for birds and wildlife. Good forest planning and management can help you manage the system so you keep your woods healthy and productive, according to the goals you have.
This series of articles will explore some of the most common vines found in Michigan. Some vines can kill trees, either through breakage from the sheer weight of a mature vine, or through strangulation by girdling. Yet other vines can provide important food for wildlife. It helps to know which you have.
To get a basic idea of which vine you are looking at, here are some questions to answer.
- Does it have tendrils? If yes, then it could be Virginia creeper, grapevine, greenbrier or poison ivy. These are the most common.
- Is it smooth without tendrils? If yes, then it could be oriental bittersweet or the native American bittersweet.
A good resource for identifying vines is online at the University of Wisconsin-Stevens Point website at: http://wisplants.uwsp.edu/familykeyv.html.
In Michigan, typical vines you may find in your woods include Oriental bittersweet, Virginia creeper, poison ivy, and grapevine. This article will focus on Virginia creeper and poison ivy, since they are sometimes mistaken for each other. The next installment will focus on Oriental bittersweet and grapevine.
Virginia Creeper (Parthenocissus quinquefolia)
This vine often grows on the same site, even the same tree, as poison ivy. Unfortunately, they can look very similar. Hence the saying “Leaves of Three, Let it be; Leaves of Five, let it thrive” used to differentiate between the two tree-climbing vines by their leaves.
Virginia creeper can be beneficial for wildlife (for example bluebirds, cardinals, woodpeckers, skunks, chipmunks, mice, deer and turkey eat the berries and parts of the leaves), although all parts are poisonous to humans
It can not only grow up as a vine up tree trunks and walls, but it can send out runners along the ground, and quickly cover the area. Virginia creeper is very fast growing. It can cover and damage a tree or shrub, but generally Virginia creeper vines do not damage the tree, as they tend to live mostly in the lower portions of a tree. When cutting vines be careful to identify this vine because poison ivy looks similar.
Poison Ivy (Toxicondendron radicans)
Identifying poison ivy is your first task. Poison ivy is often found associated with Virginia creeper, so you may have both vines on the same tree. Both plants have leaves that start out red. But Virginia creeper has a cluster of 5 leaflets, while poison ivy always occurs in clusters of three. Leaves turn greener until fall, when leaves turn bright red and orange and drop, leaving white waxy berries behind. One trick to identifying poison ivy is that the middle leaf is symmetrical and on a longer stalk than the two side leaves, which are mirror images of one another but not symmetrical. Leaf edges are usually smooth, but can sometimes be toothed or lobed, the side leaves often resembling a mitten shape.
Poison ivy vines will have hair tendrils, but no poison ivy plant will have a prickly stem, like a raspberry. Poison ivy vines are brown, attached to their support trees, and do not have shreddy bark, like a grapevine. Poison ivy has wildlife value, as birds and mammals consume the berries.
Control of Vines
Control and management of vines should be consistent with your forest management objectives. If the objective is to grow high quality timber then elimination of many vines is usually recommended. If you are managing for both high quality timber and wildlife, then you will want to leave some grapevines for wildlife and selectively manage the vines. Like all decisions, the pros and cons must be carefully examined before undertaking any action. A professional forester can help a landowner evaluate what the options are, including any cost-share possibilities that might be available to help with improving the forest.
Who to Call?
Any management system should be implemented carefully, in accordance with your forest management plan. Resources to assist you in the use of chemicals include consulting foresters and Conservation Districts foresters. Herbicides should be carefully applied, as they can also affect the trees you wish to retain.