City of Cambridge
Part of the Black Swallow-wort pamphlet produced by the City of Cambridge.
An invasive weed known as Black Swallow-wort has been spotted in Watertown, with its telltale pods. This weed threatens monarch butterflies, songbird by displacing native plants vital to them.
The problem has become pervasive in neighboring Cambridge, which started an effort to control the invasive plants. Now they plants have been spotted in parts of Watertown, said Councilor Angeline Kounelis.
“Through the years, so many residents unknowingly have thought, and continue to think, the vine with pods, should be enjoyed as an ornamental plant; absolutely not true,” Kounelis said. “The East End of Watertown has already been invaded.”
Kounelis said homeowners should notify landscapers about the issue and try to control the infestation.
“Inform your neighbors; before maturity, the vine is not difficult to pull-out,” Kounelis said.
The plants begin with small vines with shiny green leaves in pairs, have purple star-shaped flowers, and grappling spaghetti-like roots, according to an information flyer put out by the City of Cambridge. They are known to frequent chain link fences.
In summer, however, Black Swallow-wort becomes armed with seed pods resembling green chili peppers.
When they are young, it is quite easy to remove the plants, according to the pamphlet, but as they mature the extensive root system make them hard to remove.
Their spread can be prevented, however, by harvesting the green pods before they turn brown and open up. The pods start showing up in June.
To remove it from your garden, a weed ecologist from Cornell University recommends, diggin up the big root mass, but don’t put it in the compost or burn it. It should be sealed it in black plastic bags and leave it in the sun to decompose.
In Cambridge, a group known as the Pod Patrol has formed to hunt down the plants and remove the pods. They recently went around Fresh Pond looking for the Black Swallow-wort.
Find out more about the Black Swallow-wort in the Cornell article by clicking here.