Even if you do not attempt a DIY Japanese knotweed removal, ignoring the weed can cause additional problems:
If not dealt with, it can take over several metres of land, therefore costing, even more, to deal with. Potential prosecution and compensation claims against you! It will come up through tarmac, concrete and damage drains and buildings; breaking their concrete foundations. It damages the environment, which can also lead to legal action.
You may not be able to get a mortgage or re-mortgage a property with Japanese knotweed growing near it.
The removal and disposal of Japanese knotweed involve careful planning to ensure you are in line with strict environmental legislation. In the UK, knotweed does not spread via seeds. Instead, it spreads when small pieces of the plant are broken off. It can also be spread through water if the parent plant is close to a river or stream. Moving soil which contains them, or fly-tipping cut or pulled stems.