Weedy vines can be some of the most difficult to control weeds in the garden. They are fast growing, getting very large in a relatively short amount of time and often climb and cover other garden plants. These tenacious plants climb by twining, rambling, or by utilizing specialized structures like tendrils or aerial roots. They are often botanically classified as eudicots and can be woody or herbaceous, perennial or annual. Examples of vining weeds include, poison ivy, honeyvine milkweed, bindweed, and Virginia creeper. If left to grow, they can smother other plants blocking out light and killing the desirable plant.
Keeping ahead of weeds and controlling them when they are small is essential for good weed management. This requires persistence throughout the entire growing season to remove weeds as they emerge or resprout.
Pulling & Digging
Vining weeds can be controlled by pulling and digging. This method is best for small, newly emerged weeds and is done more easily after a soaking rain or deep watering. Utilize a trowel, spade, or weeding tool to dig and pull the plant out of the ground. If the vine is large, it can be pruned off before digging it out to make the process a little easier. Any portion of the vine that is above a pruning cut will quickly die and can be removed from a structure or carefully pulled or cut out of the tree or plant it is growing on.
Most weedy vines will not tolerate repeated mowing or cutting. Persistent and frequent cutting or mowing will eventually exhaust the root system and kill the vine over the period of several growing seasons. This method of eradication is only effective if the vine is never allowed to grow new top growth. Often this persistent removal of any new growth is difficult to do over several growing seasons. For this reason, mowing is not typically an effective control method for most gardeners.
Foliar Spray Herbicides
Herbicides are an effective and efficient control method for weedy vines. Systemic herbicides such as glyphosate or triclopyr can be sprayed on the foliage of the vine. This application method can only be used if the vine is not climbing or rambling on a desirable plant as the herbicide will impact any green plant it comes in contact with. Use all herbicides with care as they can cause damage to nearby plants if applied incorrectly. Consult the label carefully as not all herbicides are labeled for all garden settings. Always apply herbicides when winds are calm and temperatures are cool to prevent drift and damage to desirable plants. Protect garden plants with barriers like buckets, boxes, plastic bags, or plastic sheets to further reduce problems with drift. Herbicides must be used according to label instructions on the package. Once the vine dies, it can be removed.
Stump Treatment Herbicides
For those vines that are large and established and/or intertwined with other trees and shrubs, it is not practical or possible to spray the foliage because it cannot be reached or because of the potential of damage to desirable plants from overspray or drift. In these situations, the herbicide can be applied to the cut stump. Cut stump applications involve cutting the vine off near the base and applying the herbicide directly to the cut surface as quickly as possible after the cut has been made and the sawdust has been brushed aside. Utilize a sprayer, squirt bottle, or foam brush to apply herbicide to the entire cut surface of the stump. Only use enough herbicide to thoroughly wet the cut surface and avoid runoff.
Applications of glyphosate and triclopyr at higher concentrations work well for this application method. Glyphosate should be at least 20% active ingredient and triclopyr should be greater than 8% active ingredient.
Applications can be made anytime during the growing season, although late summer and fall applications tend to be slightly more effective.
If the stump resprouts, cut and treat again or apply a foliar spray to the new growth. Multiple applications are frequently needed.
** A Special Note on Controlling Poison Ivy
Poison ivy (Toxicodendron radicans) is a native vine common to woodland areas but found frequently growing in gardens and along fence lines. This vine causes an allergic reaction (dermatitis) in most people when their skin comes in contact with urushiol produced by the plant and present in all parts of the plant including leaves, stems, and roots on both living and dead plant material.
Control of this weedy vine requires special consideration. When working around this plant, gardeners should wear long sleeves and pants with waterproof gloves to protect the skin from the urushiol oil. Only those plants that are very small should be dug or pulled. For larger established vines, utilize the cut stump herbicide treatment to control this weed. Leave vines in place to die and decay naturally in the garden as pruning, pulling, or otherwise trying to physically remove the vines, either alive or dead, can spread the urushiol oil, potentially getting it on the skin and causing irritation and rashes.
The best control for poison ivy is to monitor frequently and remove plants promptly when they are found to avoid vines from becoming large and more difficult to control.