Least Wanted


Invasive plants are common throughout the Northeast and are spreading from disturbed areas into native vegetation. Although nearly one-third of the current Massachusetts flora is not native to the state, less than 10 percent of these species are considered invasive. The number may be small, but these plants can have a very big impact on the health of our landscapes.

It’s not just the ecology of our lands that are affected, but, in some cases, the agricultural, scenic, and recreational qualities of our region as well.

These invasives include herbs, shrubs, trees, and vines that grow rapidly, form dense thickets, and negatively impact native species and natural communities. Non-native invasives, such as Asian honeysuckles, Japanese barberry, autumn olive, burning bush, multiflora rose, garlic mustard, and glossy buckthorn, are considered by the Massachusetts Department of Agricultural Resources, New England Wildflower Society, U.S. Forest Service, and others as some of the worst invaders in the region.

In addition to the many ecological issues associated with invasive species, these plants can also degrade the scenic qualities of our natural landscapes (e.g., bittersweet choking a hedgerow of native trees), alter an otherwise intact cultural feature (e.g., goutweed taking over a formal garden), and impair agricultural activities (e.g., multiflora rose dominating a pasture, buckthorn spreading in a hayfield).

Why manage invasive plants?

Preservation of biodiversity: The loss of biodiversity is an issue of global concern. Management that protects and encourages native species, communities, and ecological processes will help maintain the biodiversity of Massachusetts. Non-native invasive plants may reduce native species diversity through direct competition. Similarly, invasive species may alter habitats and thereby impact native wildlife species.

Preservation of cultural resources, including designed gardens and landscapes, and agricultural and forest productivity. Designed landscapes require continual maintenance, often including the removal of non-native invasive “weeds.” Invasive species are also impacting the success of agricultural programs by degrading the quality of the product (e.g., hay), reducing the productivity of an area, and draining resources away from production. Examples include multiflora rose invading pastures and thereby reducing the forage available; buckthorn, bittersweet, and other woody species invading hayfields; and knotweed establishing in compost piles, thereby threatening to spread elsewhere as the compost is applied. In some instances, thick infestations of invasive shrubs have prevented seedling establishment of desirable tree species.

Prevention: The first line of defense for invasive species is prevention. The most cost-effective and complete approach to combating invasive species is to keep them from becoming established in the first place.

  • Use fill that is clean of invasive species seeds or propagules.
  • Clean equipment before transporting it between properties or habitats, especially when used in areas with known invasive species.
  • Do not plant or propagate known or potential* invasive species. Review the MA Department of Agricultural Resources’ prohibited species list.
  • Monitor new plantings, whether within designed landscapes, farms, or elsewhere, for invasives that may have been present in soils.
  • Work with neighbors to encourage these practices on abutting or neighboring parcels.

* Species that are currently known invasives in areas south of New England may migrate north as a result of climate change. As a preventative measure, the planting of these species should be avoided.


Regional partnerships are forming to deal with invasive species issues across political and jurisdictional boundaries. The Trustees are involved with the two groups currently up and running in Massachusetts: Sudbury Assabet Concord Cooperative Invasive Species Management Area and the Westfield River Watershed Invasive Species Partnership (WISP).

More resources on non-native invasive plants

Fact sheets from the USDA Forest Service Northeastern Area Forest Health Protection program: include information about specific invasive plants that exist in the Northeastern United States.

Invasive Plants of the Eastern United StatesIdentification and control: This site is an online version of the booklet of the same name. It includes good photos of the invasive plants as well as links to many invasive plant websites.

Outsmart Invasive Species AppLearn how you can help outsmart invasives in Massachusetts – it’s fun and easy.

A Landowner’s Guide to Invasive Plant ManagementHere’s a quick and handy guide with up-to-date prevention and management techniques for invasive plants in our area. (pdf; courtesty of WISP)

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