It looks festive, but it’s a “gift” that keeps growing
Wouldn’t it be great if all of the invasive species and plants we work to eradicate were terribly unattractive? It certainly would make the job easier if everything looked like a sea lamprey. Unfortunately, that’s not always the case. One of the most popular plants for fall and holiday decor is bittersweet, just Google “bittersweet wreath”.
There are two kinds of bittersweet in Michigan and most of the lovely decor you will find utilizes a variety that is damaging our natural lands. Oriental bittersweet is a non-native and very invasive plant. Using it for outdoor decorations (or disposing of it in uncovered compost heaps where birds can eat it) unintentionally facilitate its spread. Birds eat the berries, but cannot fully digest them. When they dispose of the partially digested berries, the plant spreads.
Eastmanville Bayou near Allendale is one of our properties where Oriental bittersweet has flourished. It grows rapidly displacing native plants, wrapping itself around trees, girdling them. It is so strong it can choke out and bring down a full grown tree. The plant is so prolific there, it inspired our Prescribed Browsing Project (luckily, the eco-goats think it’s delicious). In the past six years, we have had great success with the goats and student volunteers in removing bittersweet, but the battle is far from over.
There is a bittersweet to Michigan, but it can be difficult to find and identify. In many places in the United States it is considered a threatened species. There is only one American bittersweet recorded in the Ottawa County Parks system, and it has only flowered once in five years. The invasive is prolific. Please consider this when decorating for the holidays!
Sources & helpful links:
More information about invasive oriental bittersweet:
More information about American bittersweet via USDA.