Waltham Warns of Invasive Plant Species

WALTHAM, MA – The Waltham Recycling Department is warning residents about a potential invasive plant species, the black swallow-wort.

The plant is a vine with seed pods that look like chili peppers, shiny pairs of green leaves, purple star-shaped flowers and spaghetti-like roots. It can displace native plant ecosystems vital to insects, birds and other urban wildlife and threatens monarch butterflies and songbirds.

According to the Recycling Department, the black swallow-wort is spreading rapidly through Waltham neighborhoods; it's most often found on chainlink fences, though it has been spotted in woodlands, gardens and shrubs.

Because it resembles the milkweed plant, monarch butterflies will sometimes lay their eggs on the black swallow-wort in confusion. The larvae ultimately are left unable to eat or survive until adulthood.

Though the vine is difficult to dig out due to its deep roots, the Recycling Department said pulling seed pods is an important step residents can take to control its spread.

Here's a look at what steps you can take to curb its growth, courtesy of the Waltham Recycling Department:

To prevent seeds inside pods from escaping & spreading to new areas:

- Pick both green and brown pods, but be careful with the brown ones because they can open up easily and seeds can escape.

- Put the pods in a sealed plastic bag and dispose of them in the trash. Do not put pods into yard waste bags or in compost. Some people are allergic to black swallow-wort, so you may want to wear gloves.

If you find the black swallow-wort on your own property:

- Dig up the plant with entire root system, put it in a sealed plastic bag and dispose of it in the trash.

- Do not put it into yard waste bags or in your compost. The roots will sprout again and seeds are not destroyed in composting operations.

Photo courtesy of Flickr user Jonathan Rees, licensed under Creative Commons 2.0