By Susan Palmer-Wetherald

Heather Knoll stands next to a barberry at the Woodstock Post Office, removed by
Sustainable Woodstock

In the Fall, you may have noticed, on your property, while walking through the village of
Woodstock, or elsewhere in our community, an eye-catching shrub with brilliant red berries
and red foliage, among the kaleidoscope of autumn colors in our area. Unfortunately, this is not
a plant native to Vermont or even to the United States – it is the highly invasive Japanese
barberry, and its berries are dispersed by birds and small mammals, allowing this shrub to
spread quickly throughout the area.

As defined by the National Park Service, an invasive species is a non-native species that causes
harm to the environment, economy, or human, animal, or plant health. Invasive plants spread
easily, have few pests and diseases in our environment, can produce monocultures and
eliminate plant diversity, and are difficult to kill. Many of the invasive species in our area are
deer resistant, so while deer are happily feeding on our native plants, they are leaving the
invasive species to become even more pervasive. Further, studies have shown that ticks are
more abundant on certain invasive understory plants, including Japanese barberry. Vermont
State University and the University of Maine are currently conducting a study on how managing
invasive plants might decrease tick numbers and the risk of people developing tick-borne
illnesses.

Sustainable Woodstock has identified numerous invasive plants around our community. There’s
Japanese knotweed, which forms dense thickets and spreads mostly by rhizomes, aggressively
displacing native plants. It was introduced to the US from Asia in the 1800s and initially used for
erosion control. With a height of 6-15 feet and white flowers in summer, this large shrub is now
running rampant on the banks of the Ottauquechee and other rivers and streams in our area,
and on the side of our roads – greatly altering the ecosystem. In the village of Woodstock and in
gardens and land in our community, you’ll see Burning bush (also known as Winged euonymus),
an ornamental shrub which turns a bright red in the fall, often used around foundations and as
a hedgerow. It was also introduced from Asia in the 1800s and, according to the University of
Connecticut, its ability to invade natural areas was first documented in the 1970s. Other
invasive plants in our area are Autumn olive, Asiatic bittersweet, Glossy buckthorn, Goutweed
(or Bishop’s weed), several types of Honeysuckle, Mile-a-minute vine, Wild chervil, Wild
parsnip, and Yellow flag iris, to name some of the most prevalent.

In an effort to tackle the problem of invasive plant species in our community and promote the
spread of native plants and increased biodiversity, this September Sustainable Woodstock
removed Japanese barberry from the Woodstock Post Office area, with the approval of the Post
Master. There were numerous Japanese barberry shrubs near the sidewalk and elsewhere on
the property, and they were just starting to produce berries, so removing them at this time
prevented their further spread. Sustainable Woodstock mechanically removed the shrubs by
digging up the roots and removing the plants. For those root-balls that could not be extracted,
the shrubs were cut down and will be monitored for re-sprouting.

Japanese barberry has bright red berries, which birds eat and spread

For many homeowners, removing invasive plants by mechanical means is the most common,
such as by hand-pulling, cutting, mowing, and tarping. Chemical management – using both
conventional and organic pesticides – is an option for large areas of invasive plants, and it’s
recommended that it be considered only in consultation with a certified expert. Vermont
Invasives (Vtinvasives.org), a website which is a joint effort between the University of Vermont
Extension and the state of Vermont and other agencies, has information on the identification
and biology of invasive plants and on mechanical and chemical treatment options, including on
invasive plant control contractors.

Removal of invasive plants can yield quick dividends in promoting native plants. Where I
removed a Japanese barberry on our property last year, there are now native asters flowering,
adding color to the garden and serving as a late-summer feast for pollinators. Additionally,
there are many native plants to choose from when considering substitutions for invasive and
non-native plants. For example, substitutions for Japanese barberry and Burning bush could be
native Vermont plants such as Black chokeberry, with its berries and burgundy fall foliage, or
Winterberry Holly, with its red berries – both enjoyed by our local birds. Online resources
abound for selecting native plants and managing invasives. For those wanting to dig deeper, the
book Nature Action’s Guide by Sarah F. Jayne is a resource for turning your yard into a
biodiverse habitat and has a chapter with manageable guides on removing invasive plants
without herbicides. Managing invasive plants in our community is a tangible and quick way we
can protect and promote the health of our native ecosystem.