by Fred Schueler, Fragile Inheritance natural history
In a visit to the Bishops Mills Cheese Factory, recently acquired by the Municipality and progressing towards becoming a park, I found these small plants of Japanese Knotweed, Reynoutria japonica, around the gravel pad that was deposited in May 2022 when the historic plaque about the 1922 Cheese Factory explosion was put up.
There’s a dense 20 metre stand of Japanese Knotweed along Mill Street on the other side of the creek, but it looks like these little plants came as root fragments in the gravel of the pad. Under the Ontario Invasive Species Act, it is illegal to buy, sell, trade, propagate, or purposely grow Japanese Knotweed, and the invasive population is called the “largest female in the world” because it reproduces only vegetatively, from a single asexual clone brought from Japan to the Netherlands in the 1840s, to become one of the world’s most persistently invasive plants. Mature plants can be 3 metres tall, and are found around many homesites, going by a variety of names, including the completely inaccurate “Mexican Bamboo.”
These small plants can be pulled as a preliminary control, but they will need municipal vigilance, and probably herbicide, if they’re not going to take over the Cheese Factory site.
The Cheese Factory explosion was in 1924, as one can see on the corner of the plaque in the photo – sorry.