Under UK law, Japanese knotweed is classed as "controlled waste", and causing or allowing the plant to spread is illegal. For this reason, putting Japanese knotweed in your garden bin is illegal.
Japanese knotweed is very easy to spread – a rhizome fragment just 1cm can be enough to start the growth of an entire new plant. This can cause trouble when trying to dispose of the weed – if even a small piece is left or drops to the ground, an entire new plant can grow.
Since Japanese knotweed is an invasive species and the spreading of it (whether accidental or intentional) is a crime, its disposal must be handled with the utmost care.
As such, Japanese knotweed cannot be put in the bin, be it green garden waste, black general rubbish, recycling, or compost. You cannot take knotweed to any dump or tip, and you cannot fly-tip.
We’re here to distinguish the facts from the fiction regarding Japanese knotweed and knotweed treatments. There is one issue in particular that we’ll be addressing, however. There has been a spike of literature circling online promoting the message that the only acceptable way to treat your knotweed is to have it excavated. So, when should you use excavation to remove knotweed?