Taming the wild bittersweet

One of the plants we love to hate is the pretty Oriental bittersweet (we’re also not fond of Multiflora rose, also pretty).  It grows everywhere - in the pasture clogging up the grass; among the asparagus; up the trees; over the bushes; choking up whole forest parts – and is a noxious invasive.  When I first saw it in my garden in Needham, I cringed at the thought of the damage it might inflict.   My mother used to love the stuff and go looking for it to make decorative holiday wreaths with it.  She did know to stop short of suggesting I plant some though. 

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​An early encounter with bittersweet was when Kate, a new farmer in Needham, was showing me a plot of land she was about to plant.  At that time, Kate was farming on 5 or 6 private yard plots that friends and neighbors let her use (including in our back yard).  Her farm was, and still is, the Neighborhood Farm.  On this particular plot - a big yard next to the Charles River - she was showing me how the owner had dug out all the bittersweet with his excavator and telling me how grateful she was.  It had been quite a job that left big piles of dirt and plant debris all over the place.  Still, after all his efforts, we still saw bits of the characteristic orange roots everywhere in the soil (ready to make new oriental bittersweet plants!).  My, I thought, so much work for such a futile result!
 
Digging up appears not to be the solution.  Most accounts of how to deal with bittersweet suggest the following methods.   Spray glyphosate on leaves during the active growing season, and where you have made cuts.  For a less chemical method cut back the vines and squirt herbicide on the cut.  And for the non-chemical route, repeated cutting over several seasons may be enough to starve the roots of the plant.  But no matter what method you use, bittersweet seeds are everywhere, so as long as the habitat remains hospitable, the plant is likely to eventually return. 
 
When we first bought our farm in September 2019, we heard there were blueberry plants somewhere, but we could not find them.   We did find a huge pile of bittersweet in the back of our long field.  It was 200 feet long, 30 feet wide, and about 10 feet tall – a wild, thick tangle.  It seemed something good to try to get rid of, if only to keep it from spreading.  So, we started to tug at and cut the branches.  Pretty soon, among the bittersweet leaves, we found some leaves of a different kind, dark green with reddish hue, small elliptic shapes…. Hm, quite like – blueberries!  We had found our blueberry patch!  Now the vine removal achieved purpose.   Over the course of a few weeks in September and October, and with help from various people, including my dad and his partner visiting from Finland, we got to work.  One by one, the blueberry bushes emerged, while the piles of cut bittersweet vines in the field grew.  It was a lot of work! But in the end, quite satisfying!   

​The next year, we were building our house and did not remember to cut back the bittersweet, so by summer 2021, it had grown back quite densely.  Aarghh!!!  Luckily, it was not to the same point where we started from!   It took a while to cut it back.   After that, we got a little smarter and developed a routine.  We do a winter pruning of the blueberry bushes in January/February, which includes cutting back any bittersweet vines that might have come up.   In the summer, around July, we go and cut back any vines while also checking on the blueberries and picking them.  We have done this for two years now in 2022 and 2023.   The bittersweet is integrated into our routine.  We spend some extra time during tasks we would do anyway to beat it back.  Honestly, it is quite tame now, sending up a small number of thin shoots that are easy to deal with.  It is a manageable pest – at least in those blueberries.  It’s not a complete win, and we will have to manage it for as long as we want that blueberry patch, but it’s not bad either.
 
I find there is a simple insight here.  If we had tried total eradication, we might have gone in with a big bulldozer and taken out the blueberries along with the bittersweet.  Or we might have taken out the glyphosate gun, again killing the blueberries with the bittersweet.  And in both cases, the bittersweet would have come back with no blueberries to show for it.   I am not even sure the less-chemical option would have been very useful here, because that still results in the need to return and cut the bittersweet back.   Our low-tec, manual, and somewhat persistent approach has left us with healthy plants and soil, while we are also no longer bothered by this pest.   Live and let live! (albeit letting it live at a small, unobtrusive level)