Control oriental bittersweet vine in your yard before it takes over. Beautiful Fall blooms yet so destructive.
Today, I am going to discuss a problem many homeowners face. When Oriental Bittersweet vines are left unrestrained, they consume your entire yard. Oriental Bittersweet vines make beautiful Fall wreaths. The attractive yellow red cluster blooms appear in the early Fall. Although the blooms are attractive, they contain the seeds that produce the vines. The seeds grow into aggressive, invasive vines that are destructive.
What is Oriental Bittersweet?
The scientific name of Oriental Bittersweet Vine is Celastrus orbiculatus Thunb. Also known by many common names. Oriental bittersweet, Asiatic bittersweet, Asian bittersweet, Round-leaved bittersweet. Climbing spindle berry and Oriental staff vine.
Oriental Bittersweet Origin
The oriental variety is an Eastern Asian native vine (Fryer 2011). Native to China, Japan, and Korea. Introduced in the US in the 1860s. Originally used as an ornamental vine and for erosion control purposes. The deciduous woody, vines wrap themselves around plants, shrubs, trees, and anything else it can scale. As the vine grows, it chokes plants, shrubs, and trees. Weight of the vine can bring down entire trees over time. A rapidly spreading vine can grow 60 and up to 90 feet long.
[Fryer, J.L. 2011. Celastrus orbiculatus. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.]
Oriental Bittersweet Description
If you are unfamiliar with Oriental Bittersweet, we assure you it is destructive. Destructive to the garden, yard, landscape, and home. Oriental bittersweet is an invasive, climbing woody, non-native vine with dense foliage. The vines engulf garden plants and other structures. Vines attach to plants, shrubs, trees, sheds, and fences. As it grows, it wraps itself around what it is climbing.
As a result of this, the vines smother the plant, shrub, or tree that it is attached to. If allowed to grow unrestrained, it can wreak havoc on your entire landscape. Aggressive oriental bittersweet can do considerable damage in a single year alone!
Oriental Bittersweet Size at Maturity
Mature Oriental Bittersweet stems grow up to 4” and more in diameter. It climbs large trees and expands well over 60’ high. Green fruit clusters become yellow or bright orange in late Summer. In early Fall, the membranes split and bright red fruit appears. Each bittersweet fruit holds 1 to 2 seeds. The Bittersweet seeds are spread to the surrounding areas by two methods. Either the seeds drop to the ground once the membranes have split. Or the seeds are carried off by birds. Fruit clusters are striking in appearance. The fruit clusters part of the vine is attractive and in demand during the Fall season. It is frequently used to create Fall wreaths. But beware! The seeds eventually become vines. And take hold of your yard very quickly.
Oriental Bittersweet Roots
Oriental Bittersweet is an aggressive, invasive vine. It is prolific and harmful to the surrounding landscape. Oriental bittersweet roots are easily recognized. Roots are orange in color. And have an appearance of intestine-like growth pattern. We have extracted long sections of bittersweet roots 4 to 6 feet long that are 2 to 3 inches in diameter. Bittersweet roots resemble a section of human intestines although orange in color. Yuck!
How Do You Control Oriental Bittersweet?
There are two approaches to controlling Oriental Bittersweet vines. Either manually extract the bittersweet vines and roots. Or use a chemical to eradicate the vines. The manual method can be time consuming and frustrating. Manually removing the vines can make you feel overwhelmed. And even discouraged from continuing the eradication process. However, manually removing the vines is generally more effective. This is especially true with vines above ground.
A chemical method of using a herbicide with Triclopyr is effective but not always immediate. It may take a few weeks to see any improvement. The chemical method must be applied to the root system during the growing season of the Oriental Bittersweet. It is not effective during the dormant winter months when the root system is not growing.
Step by Step Process of Controlling Oriental Bittersweet
Oriental Bittersweet vines on our side and backyard were overgrown, mature vines. Bittersweet vines scaled a row of younger, maple trees about 40 feet tall. About a dozen maple trees along the rear property line needed removal due to the vine damage. Damaged Maple trees were in various states of deterioration. A couple of the trees were completely covered by the Bittersweet vines. Others were anywhere from 70 to 80 percent overrun with the vines.
Removal of the Maple trees was necessary. The Bittersweet vines were strangling the maple trees which were either dead or close to dying. Oddly enough, the Bittersweet vines were supporting the strangled trees. Preventing any of the dead maple trees from falling. The entire area trees and vines need to be removed.
These are the steps we took to regain control of our backyard from the oriental bittersweet.
Step 1. Manual approach
First step – to stop the larger heavy vines from growing any further, we cut the vines. The vines with the widest in diameter were the first vines cut. These were the heaviest and oldest of the vines. To cut the widest vines we used a folding Razor tooth pruning saw. Smaller vines (less than 1 inch) were cut with a pair of loppers. Luckily, the vines can easily be cut. The woody vine is not a hardwood but a softer woody vine.
Cut Vines Climbing the Trees
Bittersweet vines were cut so that they remained between 2 to 3 feet tall from the ground. Why cut the vines at that length? Two reasons. First, we wanted to easily locate the vines when we returned to the area. The elimination of the vines using the chemical method was to be completed at a later date. Second, a fresh cut is needed to apply a chemical weed killer. The vine will seal itself once a fresh cut is made. For the best results, the weed killer needs a freshly made cut to be effective.
Control Oriental Bittersweet Above Ground Removal
We removed a few of the entwined Bittersweet vines from the maple trees but didn’t have much luck. The vines were still green at this point. A metal rake, we found works best for removing some of the vines. Since the trees were scheduled to be taken down, we didn’t spend much time removing the vines wrapped around the Maple trees. However, if the trees were to remain it is best left with the entangled branches until they have dried out. Especially when they are so far up above ground level. Attempting to pull entangled vines from a healthy tree is risky. Tree branches can break and cause injury to the tree. Or the vines can snap and whip you as you pull on them.
Allow Vines to Remain in Trees Until They Dry Out
Generally, we allow the vines to remain on the tree until they dry out. The vines that you can reach can be removed with a metal rake. Vines that you are unable to reach will drop to the ground overtime especially during a windstorm. Some of our maple tree branches still have a few old bittersweet vines that were cut down three years ago. As sections of the vine dry out, they eventually fall out of the trees.
Within the next few days, the row of maple trees were taken down by a professional tree removal service team. After the tree removal was complete, we were ready to treat the vine root system. Using the chemical approach below in step 2.
Step 2. The chemical approach
Once the professional tree removal team finished, we returned to the area with vines in the ground. Using our loppers, we made a fresh cut as close to the ground level as possible. Cut the vine as close to the vine root systems as you can. Always wear disposable gloves for protection. Apply an herbicide containing Triclopyr to the fresh cut. Use a disposable foam brush to apply the herbicide. After each cut, immediately brush the exposed bittersweet vine stem with the herbicide. In some instances, roots grew slightly below the ground level in a horizontal manner. To apply the herbicide to those roots, we made a notch on the root then applied the herbicide.
Control Oriental Bittersweet – Effects of the Herbicide
The Bittersweet root system absorbs the herbicide. Herbicide travels and infects the entire root system. Herbicide slowly kills the root system. Bittersweet roots turn completely black when they are dead.
Again, the herbicide is most effective on fresh cuts. Apply herbicide as close to the root system as possible. Herbicide application is applied only during the growing season when the roots are active. Effects of the herbicide is to stunt the root growth. And eventually kill the vine from the inside of the root system. For best results, apply herbicide to the vine root system on a dry day. Then the treated vine should remain dry for a minimum of 24 hours.
Control Oriental Bittersweet – Protect Surrounding Areas
Another consideration is the proximity of other garden plants. Herbicides will damage surrounding plants if accidentally applied to them. We noticed one vine root grew right next to a Maple tree root. The Maple tree was a mature 50 foot tall tree. A tree we did not want to lose. Sometimes it is better to manually extract the roots rather than risk losing other garden plants.
When using herbicides, protect the surrounding areas. Lay a tarp or clear plastic to the garden areas.
Step 3. Root Removal
After several weeks, we removed the dead bittersweet roots in the ground. Most of the root system should easily be pulled up from the ground. Any part of the root system that couldn’t be pulled up, could be cut out of the ground. We found the vine root system to be quite extensive within our yard. Most of the backyard had several layers of roots growing below the soil surface. So incredibly invasive!
Step 4. Oriental Bittersweet Disposal
We were careful to dispose of the bittersweet vines and root system. Both vines and roots were bagged. And placed with garbage for the landfill. None of the bittersweet made its way to our compost bin. You never want any seeds or partial root systems to take hold of the compost bin.
Terrain Shop, Westport, CT
Terrain at Westport, Connecticut. Store display of Oriental Bittersweet Vines at their Westport location. Hmmm. One person’s junk, is another’s treasure?
Oriental Bittersweet – Final Note
So we started this project from a point of feeling overwhelmed. Did we arrive at complete eradication of oriental bittersweet? No, not exactly. My best guess is that we have some level of control of the bittersweet. Probably 80% of the oriental bittersweet above ground has been eliminated. Below ground level, there is quite a bit of the vine root system. Some of the root system might be rotting from within but some appears to be viable.
Next Spring, we’ll have a more accurate idea of how successful we’ve been at controlling the bittersweet vine. One thing we are certain of? There is more work to do in this ongoing battle against the oriental bittersweet vine.
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