Japanese knotweed


Which chemical I can use, to kill the Japanese knotweed. And where to buy. I’m in Canada Ontario


Japanese Knotweed is a common enough weed in Ontario gardens and getting it under control will test the most ardent gardener so patience and perseverance is called for.

Below you will find a super link to the Ontario Invasive Plant Council handout on Japanese Knotweed.  It is a very thorough publication which gives all kinds of useful information about the plant but if you scroll to page 18 you will find a comprehensive list of control measures for you to try – manual, cultural, chemical & biological.


If, after trying manual & cultural control methods, you have to resort to using a chemical herbicide, I would suggest you contact a licensed weed control specialist in your area to ask their advice or get them to deal with the problem safely.

Hope this helps.