New Invasive Plant Alert--Black Swallowwort

The Time To Act Is NOW
Black Swallow Wort Overtaking A Field
Black Swallow Wort Overtaking A Field

Black swallowwort is a new invader to West Newbury. It has been found in several locations on private and public land, but is still small.

Please help us map this new invader, record its location, and control it while we can.

Locate and Map: 
Black swallowwort is most likely to be found in open field, edge of lawns, or roadsides. This vine in the milkweed family is has dark, glossy leaves that are come in pairs (opposite), and have tendril like vines, like Asian bittersweet. It has small, dark purple to brown flowers in June, and slender milkweed pods in July/August. See this brochure for ID tips:

If you find black swallowwort (in West Newbury), please take a photo and record the occurrence in iNaturalist. If you are on public land, keep the geoprivacy Open. If you are on private land, and want to obscure the geoprivacy, join this Project, and share the location with the admin so that we can follow up and track the invasion.

You can also email a photo to, with location information.


Left alone, black swallowwort will take over entire field and smother other plants. The time to control them is when they are small. They can be dug out with a shovel-- make sure to get all the fibrous roots and check back to resprouts. If it's on your land and it's not near a wetland, you can also use Brush-b-Gone or Round Up to spray the plant when it's in flower (June). Roots tend to break when plant is pulled; but pulling is better than nothing. It's important to stop the plants from going to seed, as it spread far by wind.Control & Eradicate

We have a window of a few years to control and eradicate this plant in West Newbury.  Please help us map and control this plant in 2021, and join the fight to Stop the Swallowwort.