Invasive Plants are a Serious Issue! by Sustainability Tyngsborough member Amy Pozerski

Invasive plants are not typically on most people’s radar. However, as climate change continues to progress, now is when we need to start taking this topic seriously. Invasive plants are always non-native to our area and most times very aggressive. These plants are prolific in large part because their natural predators don’t live here, and if nothing is feeding on these plants, their population can explode quickly. This, in turn, crowds out native plants that are so important to our local wildlife, mammals and insects. 

Black Swallow Wort

Black Swallow Wort (Cynanchum Louiseae): A perennial climbing vine that flowers in early summer and produces seed pods late July and early August. The seeds are spread by the wind. Monarch butterflies mistake the plant for milkweed and lay eggs on it, but the larvae cannot feed off this plant and end up dying. 

Japanese Knotweed

Japanese Knotweed (Reynoutria Japonica): A perennial that can grow from three to fifteen feet tall, it has bamboo-like stems and can tolerate many different soils and levels of shade. The seeds spread by wind, water, animals, and humans. Japanese Knotweed also spreads by underground roots and can even sprout from a piece of stem the size of a fingernail. Once it gets a foothold somewhere, it spreads like wildfire and can be nearly impossible to eliminate. It creates a mono-culture that makes an area uninhabitable to our native wildlife.

Purple Loosestrife

Purple Loosestrife (Lythrum Salicaria): Mainly found in damp areas and wetlands, it has showy purple flowers arranged on flower spikes. The plant spreads primarily by seeds. Each mature purple loosestrife plant can produce up to 2.7 million seeds annually! This plant creates dense thickets in wetlands, crowding out habitat for wetland wildlife and altering the movement of water within the wetlands.

Oriental Bittersweet
Oriental Bittersweet

Oriental Bittersweet (Celastrus Orbiculatus): A woody vine that grows rapidly and clings to anything up or down that it comes in contact with. It can easily climb trees up to 100 ft tall! It is spread by seed and fruits, eaten by birds and deposited. It also spreads by underground roots. The vines grow in diameter as they twine around tree trunks and literally chokes the plant that it is clinging to. Due to the weakened plant and the weight of the bittersweet vine, tree canopies can come crashing down when you least expect it. 

  • Want to learn more? Check out the following resources:


  • Bringing Nature Home, by Doug Tallamy (every homeowner should read this book!)
  • Invasive Plants: Guide to Identification and the Impacts and Control of Common North American Species, by Syl Ramsey Kaufman & Wallace Kaufman