If you’ve found Japanese knotweed growing on your property and don’t want it there, you may need to take legal action against the owner of the land where it has grown. This guide will teach you how to claim Japanese knotweed as trespass, so you can get your property back to full health and full value.

What is knotweed?

Knotweed or Japanese Knotweed is an invasive plant species which was brought to the UK in the early 1900’s as a decorative plant, unbeknown that it spreads like wildfire and can cause damage to property and amenities. Knotweed ryzomes (root system) and root growth can grow vigorous and can even grow through tarmac, concrete, water pipes, sewer pipes and can get into property foundations and cause havoc.

Knotweed can grow up to 8 inches a day in the summer and grow as tall as 12 feet high. The stems grow thick like bamboo and small stems grow from the main stems and grow a thick bush of leaves and even flowers through August and September.

What does trespassing mean?

If something from another person or property comes on to your property or land without your knowledge or consent, that is considered to be trespass. The fact that Knotweed has come from another parties land on to yours, and causes devaluation and other problems and can cost you money to put right, this is a recoverable trespass issue.

What are the options to resolve this issue?

If Knotweed is coming from a neighbour, the best approach in our opinion is to speak with your neighbour and try and get an amicable solution between you both. A survey and treatment plan with an Insurance Backed Guarantee will ultimately help both of you. If the Knotweed can be seen to be coming from your neighbour to your land quite obviously, your neighbour may agree to pick up all the costs. This is something hopefully as neighbours you can sort out.

If your neighbour doesn’t listen to your friendly request, you should put it in writing and allow them a small amount of time to get some resolve. Knotweed will only grow and spread if it is left and that will be worse for everyone.

If the Knotweed is coming from a commercial neighbour like the railway or council land or a commercial enterprise, report it formally so you have a record. Many times we see that although reported, the commercial entity doesn’t take it seriously enough or carry out proper treatment, then the problem again will only worsen.

The fact that Knotweed will not go away on its own, and a typical treatment plan with an Insurance Backed Guarantee can cost a few thousand pounds, you need to ask yourself should you pay for it if the neighbour is at fault? Then you need to think about any damage to your property and any devaluation because of the presence of Knotweed, and ask if you are happy with that or want to take action to protect your own asset.

If you decide to make a claim against the neighbour land owner, you can typically do this on a No Win No Fee. You should be able to recover the full cost of a treatment plan and force your neighbour to treat the Knotweed on their land to ensure it doesn’t come back again. You should also be able to claim the cost of the Insurance Backed Guarantee, and cash compensation for the devaluation of your property because of the presence of Knotweed. This may be an average of 10% of your property value, so a £200K property should start a claim for £20,000 plus treatment plus guarantee and maybe some additional compensation for inconvenience.

Which option should I choose?

The choices are really down to you. As your house and property is usually your biggest asset, it is important that you take this seriously and probably that you seek expert legal support to ensure you are fully protected.

How much will it cost me?

Japanese Knotweed Agency offer a FREE – WITHOUT OBLIGATION On-site Survey anywhere in England & Wales, which will give you all of the information you need to make a decisive way forward. The Survey Report will give you information on where the Knotweed has travelled from, its age, all identified crowns and growth areas, any potential damage caused by the Knotweed, and will also report on up to 58 other invasive weeds if any of those are present.

Your Survey Report will also come with a full quotation for treatment and a 10-year Insurance Backed Guarantee that if any Knotweed comes back after the treatment and within 10-years, it will get treated for free under the guarantee.

The Survey and report are 100% FREE and WITHOUT OBLIGATION

With that information you can then decide how to proceed and whether to move forwards with any legal claim. The options are then yours with detailed information at hand.

Request your FREE Onsite Survey here:


When should I claim Japanese knotweed as trespass?

As above, if you are friends with your neighbour and the Knotweed is coming from their land to yours, it may be best to speak together and try come up with an agreement.

If the neighbour doesn’t take notice or take action, the Knotweed will only get worse week by week, so you shouldn’t wait too long before taking action, whichever route you choose.