Japanese Knotweed Information


We moved into our North Toronto home in 2004 and we failed to ask the previous owners what all the plants were in the garden.
Since then I’ve always wondered what the strange plant was in the corner.
Every year it grows to 6′ to 8′ and every year it dies only to return the next year doing the same thing. It leaves long hollow brown stems that aren’t don’t show any new growth – i.e. it grows from the ground completely. There are multiple stems from the ground that grow.
I thought bamboo (or in that family) since it seems to have segmented stem.
Heart shaped alternate leaves.
Any help?
Thanks in advance!







Thank you for writing to Toronto Master Gardeners with your question, as it takes the vigilance of homeowners like yourselves to help with identification of plants that are, in this case, known to horticulturalists as a highly invasive plant — Japanese Knotweed.

While your photo is a titch hard to read, your description alone lays out the vital characteristics of this undesirable plant. We’ve added another photo here clearly illustrating the ‘heart shaped” leaves, although this hollow-branched plant itself does not earn a lot of love.

Please know that you’re not alone with this rogue, persistent, plant: here you may read a very complete description by Toronto Master Gardeners as to how we can all be vigilant with effective management of JAPANESE KNOTWEED in our gardens and adjacent public areas.

Also, for yourself, and all concerned readers, here is a link to the Facebook page  by Japanese Knotweed Ontario РEradicate.