Riparian and roadside invaders


Illustration by Anne Hunter

While many of Vermont's watersheds are impaired by the invasive plant Japanese knotweed (Fallopia japonica), anecdotal information suggests it is just getting established in the Batten Kill watershed. In 2005, BCCD reached out to riparian landowners on the main stem and larger tributaries with an offer to treat Japanese knotweed along their streambanks. At the same time, BCCD and the Bennington Garden Club hosted an event to promote that initiative and solicit volunteers. The event - "Invasives: Meet Them, Eat Them" - treated participants to snacks which included invasive species as ingredients. Some of those recipes are available here: Knotweed and Garlic Mustard Delights.

Surveys conducted in 2006 and 2007 by Student Conservation Association interns working with the Green Mountain National Forest and BCCD confirmed that Japanese knotweed is relatively uncommon in the Batten Kill watershed. In years to come, BCCD and the Forest hope to implement an "early response" program to treat these invaders.

garlic mustard

Garlic Mustard
Illustration by Anne Hunter

For some invasive plants, road crews are a primary (albeit unwitting) vector of movement along roads and to and along watercourses. Mowing machines move seeds of purple loosestrife, garlic mustard, wild chervil, and wild parsnip. Graders and ditching equipment carry rhizomes of purple loosestrife, common reed, and Japanese knotweed. Stockpiled ditch spoils, when used in another location as fill, can spread rhizomes of invasive plants to new locations. Even vehicle wheels can carry plant parts from place to place.

In 2007, with a grant from the Vermont Watershed Grant Program (which is supported by sales of conservation license plates), BCCD produced a Powerpoint presentation on managing roadside invasive plants for road crews. The slideshow is available online here in PDF format and here in video format.

For more information on invasive plant species, refer to: