If your neighbour fails to treat a Japanese knotweed infestation in their garden and the Japanese knotweed starts growing in your garden, you may have a claim against your neighbour for any damage to your property caused.

What is Japanese Knotweed?

Japanese knotweed is an invasive non-native plant. It spreads very easily and is an extremely strong plant that can cause structural damage to buildings.

Is it illegal to have Japanese knotweed growing in my garden?

No. However, it is unlawful to allow the knotweed to spread into the wild and you can face legal action if it spreads onto any neighbouring property.

How do I treat Japanese knotweed growing in my garden?

Japanese knotweed cannot simply be dug up and thrown away. If you do this, it will simply grow back. It usually has to be chemically treated and properly disposed of.

The Environment Agency provides advice about how to deal with a Japanese Knotweed infestation which can be seen here.

Generally, you are best to instruct a company specialising in Japanese knotweed removal. Such companies are able to complete eradication programmes, which last several years, and then provide a guarantee upon completion of the treatment programme.

How do I make a claim against my neighbour?

If your neighbour has allowed knotweed to spread into your garden, you should tell them about this. If they do not agree to arrange for a treatment programme to be carried out, you may be able to bring a claim in nuisance against them.

If you bring claim in nuisance, you can obtain an order making them carry out a treatment programme. You can also ask for compensation for any damage to your property, including damage to your garden.

In a recent case, I managed to get my client’s neighbour to agree to do the following:

  • Complete a 5-year eradication programme
  • Provide a 10-year guarantee upon completion of that programme
  • Pay my client £8,000 in compensation for the damage to her garden
  • Pay my client’s legal costs.