One of the most asked questions from homeowners is; “Is Japanese knotweed illegal to have on my property in the UK?” The simple answer is “no” it is not illegal to have Japanese knotweed on your land or property, however there are legal consequences if you allow it to spread.

How does it spread?

Japanese knotweed spreads via underground root systems called rhizomes. Knotweed plants in the UK do not have viable seeds but these rhizomes can grow underneath fencing from your property to a neighbours. This applies to residential and commercial property or land.

Am I responsible for knotweed?

If you have Japanese knotweed on your land or property (even if you do not reside there) you are responsible for controlling it either by having a herbicide management plan in place (typically a 3 or 5 year plan) or by having it professionally excavated. Most importantly you must NOT allow it to spread. Failure to do so will result in problems and possible legal issues starting with the most common – encroachment.

What is Japanese Knotweed Encroachment?

If Japanese knotweed is allowed to spread beyond the property boundary this is deemed as “encroachment” and this applies even if just the underground rhizome (root) of the plant is found to have spread from one property to another. If this happens the relevant law is that of “private nuisance”, which is defined as “an act or omission which is an interference with, disturbance of or annoyance to a person in the exercise or enjoyment of his ownership or occupation of land”.

Actionable private nuisance claims can be served against persons found responsible for having allowed or caused Japanese knotweed encroachment to take place.

What if knotweed has encroached from a neighbour’s onto mine?

Japanese knotweed spreading from a neighbour’s garden is their responsibility, so if knotweed has spread onto your property, you could take action against the neighbour.

What should I do?

Let’s start with what you should not do.

Do not try to treat or get rid of knotweed yourself. The big problem is you may be at risk of being prosecuted if found guilty of disposing of Japanese knotweed in the wild as knotweed is deemed as ‘controlled’ noxious waste and therefore has legalities around its disposal. All knotweed waste is required to be taken to a licensed landfill by a contractor with the appropriate waste carrier’s licence.

What you should do is a) get legal advice and b) have a survey carried out by a qualified Japanese knotweed contractor. We can help you with both.