Japanese Knotweed

Japanese Knotweed (Fallopia japonica) stems have distinctive features that make them identifiable throughout the year. During the summer, these stems grow 2 to 3 meters tall and resemble bamboo. They are characterized by their hollow structure and distinctive purple speckles, which stand out against the vibrant green leaves found at each node. This bamboo-like appearance is a key indicator of Japanese Knotweed, making it easier to spot during the growing season.

As the plant matures and transitions into winter, the stems undergo noticeable changes. They become hollow, turn brown, and become brittle, contrasting sharply with their summer appearance. These brown, brittle canes often remain standing through the winter months, providing a clear indication of the plant’s presence even after the leaves have fallen. Recognizing these stem characteristics is essential for identifying Japanese Knotweed at various times of the year and implementing timely management practices.

Locally, the plant was present on the north shore, and the shore owner was extremely gracious and said she had been trying to get rid of it, but it just keeps growing. So far, we are only aware of that one patch, but if left alone, it will spread. At this time, it’s taking up a third of her shoreline. It is not recommended to mow, as that spreads chopped up pieces and these will take root. It’s suggested to cover them with a tarp leave and it in place for 5 years.

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