This section has been provided and developed by Shelly Stiles, Bennington County Conservation District Manager and members of the District.
Non-Native Invasive Species – Overview
Native plant populations throughout Vermont are being supplanted by non-native invasive plants. To the extent these invasions are successful, habitat “services” provided by native plant communities – food, protection from prey and weather, places for breeding and nesting, regulation of water temperature, and others – are diminished. Along streams and rivers, water quality too is impaired, as organic inputs are altered, runoff regimes are changed, and banks are destabilized by plant species whose roots are rhizomatous and ill-equipped to protect banks from erosion.
In 2003, the State of Vermont adopted a Noxious Weed Quarantine rule to regulate the importation and movement of a number of invasive plants. Many of them are familiar to gardeners and naturalists in the region, and include goutweed, garlic mustard, bush honeysuckles, buckthorns, and purple loosestrife. It is illegal to move or sell these species.
The State has also put several invasive species on a Watch List, which includes such common species as Norway maple, dame’s rocket, yellow flag, reed canary grass, and multiflora rose. The Watch List has no legal status, but is a useful tool for those who sell, purchase, or grow plants and want to avoid those that are problematic. For more information on these lists, refer to the website of the VT Invasive Exotic Plant Committee, VT Invasive Plants.
To learn more about non-native invasive plants common to Bennington County and how to manage them, refer to our brochure, “Guests Who Won’t Go Home: Managing non-native plant species in home landscapes, fields and forests in Bennington County, Vermont”.
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, the Bennington County Conservation District (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.
Riparian and Roadside Invaders
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.
Links to other resource materials:
- Vermont Invasives
- Vermont invasive plants
- The Nature Conservatory site on invasives
- Stiles, Shelley. “Treating an invasive plant.” The Bennington Banner. 6 September 2010. Web