Invasive Plants at Viles; Asiatic Bittersweet

As with much of the historic agricultural land across New England, Viles Arboretum has found itself home to an overabundance of invasive plant species.

Invasive species are defined as species occurring outside their natural range which are able to reproduce within their introduced range and presents a threat to native species or ecosystems in which they inhabit. Frequently these species are capable of outcompeting naturally occurring species for resources and have few or no limiting factors in their introduced range, allowing them to spread uncontrolled. 

You don't have to travel far along the trails to stumble across a variety of invasive plants. A recent survey conducted by the Maine Natural Areas Program revealed 18 different species, which are classified as invasive, across the Viles Arboretum property. Some of the most common species include honeysuckle, Asiatic bittersweet, multiflora rose, autumn olive, buckthorn and burning bush. These species can be found laying claim to the foundation of the Piggery, creeping their way into the Johnson Pavilion and scattered about the woodlot and fields. 

While many of these species are likely here to stay, Viles Arboretum is dedicated to mitigating the risks associated with the invasive species present on its 224 acres of preserve land. Over the course of the next few weeks, we will be highlighting some of the most prevalent invasive plant species found at the Arboretum, and what strategies are being taken to reduce their impact.  

This week we are highlighting Asiatic bittersweet.

Asiatic BittersweetAsiatic Bittersweet

Introduced to the U.S. in the mid 1800's as an erosion control method, the abundant bright red berries also made Asiatic bittersweet a popular choice as an ornamental vine. Thick, fast growing vines wrap around trunks of trees, continuously climbing till they reach the tree canopy. These heavy vines are capable of damaging, or even killing, their host trees as their limbs to snap under the weight of the vines. 

This species is capable of sprouting from root fragments, making them difficult to completely remove from an area without the use of chemical herbicide. Berries, which are attractive to many native bird species, allow the species to spread via seed dispersal in bird droppings. Use of bittersweet berries in wreaths and flower arrangements provides another opportunity for seeds to travel. 

Staff and volunteers are actively taking measures to suppress Asiatic bittersweet at Viles Arboretum using methods recommended by the Maine Natural Areas Program. Large vines are cut at chest and ankle height to prevent the climbing of old vines by new vine growth. Smaller plants are pulled out by the root whenever possible. Plant removal projects are conducted before the plants are able to begin producing fruit to help reduce the plants ability to spread through seed. 

You can help prevent the spread of Asiatic bittersweet by planting native ornamentals and using native berries in wreath and flower arrangements.

Our work at Viles Arboretum is made possible by the generous support of our members and donors. If you'd like to help sustain our efforts, consider becoming a member today.