Simply put Japanese Knotweed is not poisonous, and isn’t harmful to humans like other invasive species. In fact the knotweed can be used as a food source with a taste and texture likened to rhubarb. Apparently it can also be brewed into a type of beer.
Now we are not suggesting you rush out and cook up a nice pie. We have no first-hand knowledge of eating knotweed, and certainly don’t encourage you to try because the off-cuts would need to be very carefully handled. There is plenty of literature online to further any interest you may have in Knotweed as a potential food source. It’s doubtful if this will be the solution for an infested development site though.

2021
Everything you wanted to know about Japanese Knotweed but were afraid to ask
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