Bittersweet Battles

Photos by Kevin Shields.

The Damariscotta River Association (DRA) property in Newcastle, Maine, sits perched between US Route 1 and the Great Salt Bay. Over the past 50 years, this former pasture land has spawned a white pine community that is now under threat from oriental bittersweet (Celastrus orbiculatus), an exotic invasive vine that strangles, smothers, and overburdens native vegetation. With DRA permission, I’ve been working to control this invasion. “Control” is a key word here, as those familiar with bittersweet will know that it’s probably impossible to eradicate a large, established infestation.

In my 40 years of mechanically battling oriental bittersweet, I’ve learned that only one approach will provide any measurable result: persistence. As Calvin Coolidge once noted, “The slogan ‘press on’ has solved and always will solve the problems of the human race.” Press on indeed, since it takes about two hours of tedious, repetitive, back-breaking labor to clear 150 square feet of bittersweet in an intensively infested area.

Bittersweet stems and roots form a nearly impenetrable tangle that can completely dominate an area, so the first challenge of any control effort is to clear space amidst the thicket. Cutting the plant itself is a simple task. Bittersweet has a soft, woody stem that can be easily sliced through with hand-held pruners or lopping shears. Only very old stems achieve a diameter that requires a saw, and even then a small folding saw will do nicely. Some may feel the need for power in the form of a brushcutter or chain saw, but I’ve found that both tools are of limited utility in a thicket of dreadlock intensity.

My particular method is to cut each stem about 4 feet from ground level. I then attempt to pull the remaining stem out of the ground. If the rooted stem gives more resistance than my back and arms can take, I simply cut it at ground level. The gap between where the first cut is made and ground level serves two purposes. First, it provides a quick visual cue as to where the work is complete, which is important when working an extensive and complex site over an extended period of time. Second, the cut stumps will generate new shoots that will reach for a handhold to rescale the tree. The gap impedes this process.

Pulling bittersweet out by its roots essentially rototills an area. As the main root stem arises, it turns over the soil in chunks, followed by masses of fibrous roots that are matted with clumps of soil. The ground can be pleasingly friable, with a just-tilled look. This may ultimately be a problem, as seeds will fall into an area of optimal growing potential.

Once the stem and root are pulled from the ground, I fetch them up in pile, or on top of a dead branch, so that they are sure to dry out and die. Bittersweet’s ability to re-root may not match its athletic growth characteristics, but there is little sense leaving that to chance after the spine-spraining struggle to remove it from the earth.

 

Estimating just how much time it will take to control a particular infestation isn’t easy. In 40 hours I have worked over a half dozen acres, and there are at least that many more to go. Early on, the clearing was conducted more intensively with lots of root pulling, while later efforts leaned more toward simple cutting. The forest edge, with its abundant sunlight is generally more inundated with vine growth, as well as other plants that impede progress. The work in the forest interior is somewhat less inhibited.

 

The leaves on the cut stems wilt and then flutter to the ground, creating an October mood in the mid-June forest. The larger pines and oaks will now thrive for decades without their cloak of vines. However, the smaller- to medium-sized specimens remain vulnerable to reinfestation without follow up efforts. Many of these stems are so disfigured that they’ve certainly lost any economic value as timber. Yet, the bittersweet growth clock has been set back to day one, and with persistent effort will remain a nuisance rather than a disaster.

 

Practice Safe Wreathmaking

Oriental bittersweet was first imported to the United States in the 1860s as a landscape plant. Little did people know back then that the plant would become a maligned forest villain.

Today we know better, sort of. While it’s illegal for garden centers in many Northeastern states to sell oriental bittersweet plants, the plant’s branches and seeds are still sold, and spread, by people who make and distribute holiday wreaths made from naturalized oriental bittersweet.

If you’re going to buy a roadstand bittersweet wreath, or drive to the next town over and plunder vines from a farmer’s hedgerow to make your own, be aware that you’re engaging in at-risk botanical behavior. If you burn the wreath when you’re done with it, you may be all right, but abstinence is the only sure way of preventing unwanted bittersweet infestations around your compost pile. NW

 

Photo Gallery

 
Discussion
  1. Lois Fay → in Charlton, Mass
    Feb 11, 2011

    How can you talk about oriental bittersweet without being obscene?
    I am supposed to be the steward of a small (4.2 acre) plot of land entrusted to a tiny land trust organization. When I first walked the property, I was enthralled. It seemed a perfect situation for my dream project, that of a butterfly, pollinator sanctuary. Sadly,the wooded area very quickly became choked by that monster. My dream lives on, though. I need a person to perform an ecological appraisal of that land. I like the term environmental census. How much should it cost for such an examination? I need realistic dollar figures, in order to apply for a grant. Please refer me to persons offering such services. I am in South Central Mass.

  2. dave → in corinth
    Feb 14, 2011

    Hi Lois,

    I talked to a friend up here who does this kind of work, and she said that they charge $52/hr for assessment work, and that for a lot your size this would take approximately 2 hours for field work and 3-5 hours to do a map and a management plan. This obviously doesn’t include the cost of treatment. She spoke highly of a guy named Chris Polatin at Polatin Ecological Services in MA. You might look him up and ask him what he thinks.

  3. Suomela → in Ambler, PA, USA
    Jul 07, 2015

    Thank you for your article on Asiatic Bittersweet. Growing up with ‘Timber Harvesting’ and ‘Northern Woodlands’ magazines in the family home, I saw your publication carried a gravitas appreciated by my small woodlot-owning father and uncle. 

    I myself, an out-of-stater in Maine-speak am coming up north and warning my family about the threats of this terrible vine. I see what it is doing in the green spaces of Philadelphia, PA. The complete suppression of growth on what few seedlings the deer dont eat, and the girdling and shading out of all young to large sized trees. And winter fall/breakage of softwood branches from the strain of the vines compounded by the weight of any ice/snow from storms.

    I always knew Massachusetts had a terrible kudzu problem, and that loosetrife, knotweed, and milfoil were plant invaders in Maine.  However, I never heard of Asiatic bittersweet, and even with an active interest in this topic (Im now supporting a land trust as a volunteer preserve steward) I never saw bittersweet in my readings, and once aware, found others who I shared this information with equally perplexed. 

    Aside from our insect and fungus invaders, I see Asiatic bittersweet as the largest threat to our forests.  And too few people know about it.

    It is a terrible threat, for its girdling, strangling, thick spreading roots, and aggressive complete colonization where present.  People might not realize, this is a WOODY vine.  It has the strength of a dog lead and yet the flexibility and propensity to grow like a morning glory vine.  Further, the presence of one plant means an almost 100% likelihood of spreading within 5 miles, as the seeds are so favored by birds and thus well dispersed. They are successful in sprouting.

    For those managing woodlands, even for your trees that survive, dropping a tree with vines in the top can easily add 20 minutes to a single normal cut. We dont have (native) grape or virginia creeper in our (northern) Maine forests and so arent used to this extra burden. The Bittersweet even further complicates tree felling. The recent 295 corridor widening near the Freeport exits must have been a dangerous, frustrating ordeal with all of the bittersweet tangled in those trees.

    And so, my comment for readers of this article who love and care about our northern woodlands - this is one plant to know.. and put sweat labor behind reducing/eradicating.

    For a Northern Woodlands writer/editor,  can you refresh this topic and write an update article for your readers? 

    Thanks much!!

  4. Jon → in Dover, NH
    Aug 09, 2017

    Here is an update/addition for anyone that may be reading this now ancient article (assuming that is okay with NW).

    The following paragraph was edited out of the article, but is still relevant.

    Clearing an area depends on the level of infestation. If the vine has seeded in recently, this can amount to some simple cutting and pulling. An example of this would be a hedgerow in a yard. Such an area that is not generally tended, other than occasional pruning or raking, is vulnerable to bittersweet introduction. A branch could be down that facilitates the jump of the vine to the tree, and the initial vine growth among the other plants is not particularly noticeable. Like a cancer that has been detected early on, this is when eradication can be completely successful, especially if an eye is kept on the inevitable sprouts, and they are quickly dispatched.

    I am noting this now because there is so much land, public and private, that is in the early stages of infestation. Most homeowners, park managers and professional landscapers seem to be completely unaware of invasives. A worker shaping a forsythia that is overwhelmed with bittersweet clips it into one mass as if there is no difference.

    I can also tell you that DRA, the land trust mentioned in the article, never followed up with me about my work or the article. They do continue to ask for cash donations!

Join the discussion

To ensure a respectful dialogue, please refrain from posting content that is unlawful, harassing, discriminatory, libelous, obscene, or inflammatory. Northern Woodlands assumes no responsibility or liability arising from forum postings and reserves the right to edit all postings. Thanks for joining the discussion.

Please help us reduce spam by spelling out the answer to this math question
one plus two adds up to (5 characters required)