Japanese Knotweed: Knot In My Backyard!

Japanese knotweed has in recent years attracted much media attention. The plant is often known as an “alien species” by the European Union and in an international context can cause significant problems to homeowners for the following reasons:

• It can cause physical damage to the properties which can affect the value of property;
• It can be difficult to market a property with Japanese knotweed because there are problems obtaining insurance and mortgage for such properties;
• It can be difficult to eradicate Japanese knotweed.
• It can result in civil and criminal liabilities if it is not treated in accordance with the law

Japanese knotweed was initially introduced to the UK by the Victorians in the 19th century and is now seen as the most invasive plant in the UK.  It can grow to a height of 3 metres and at a phenomenal rate and easily reproduces from small offshoots. It can often stay dormant for several years before starting to regrow. It can creep underground and can break through tarmac, concrete and damages drainage pipes and foundations. The plant can also increase the risk of soil erosion and flooding.

Buying a Property

It is common knowledge that when buying or letting a property the normal rule of caveat emptor applies and where a property is sold or let the seller or landlord is not under a duty to disclose any information about the physical condition of the property.

When it comes to Japanese knotweed, it is wise to carry out adequate enquiries to establish the presence as otherwise there could have dire consequences, as set out above. The standard enquiries may reveal the existence of Japanese knotweed. If not, an additional enquiry could be raised by your conveyancer specifically addressing the issue of existence of Japanese knotweed. Usually, however, the seller or the landlord will simply ask that the buyer or tenant rely on their own enquiries. The buyer will then either have to rely on their own surveyor or obtain specialist advice if they suspect the existence of Japanese knotweed.

If an owner allows Japanese knotweed growing on his land to spread onto neighbouring land then there is a risk that an owner or occupier could become liable for common law or statutory nuisance. The owner of the neighbouring property may be able to take common law private nuisance proceedings for the following:

1. The loss of enjoyment
2. The costs of removal; and
3. A continuing injunction against re-infestation.

Furthermore, Japanese knotweed is one of the plants listed in Part II of Schedule 9 to the Wildlife and Countryside Act 1981. A person is guilty of an offence where they plant or otherwise cause to grow in the wild any plant that is included in Part II.  It is possible to argue that a landowner who allows Japanese knotweed spread to other areas and who makes a decision to do anything about it could be committing an offence under this section.

Anyone found guilty of an offence under his section is liable:

• On summary conviction in a Magistrates Court by up to six months’ imprisonment and/or an unlimited fine;
• On conviction on indictment to two years imprisonment, a fine, or both.

Offences can also be committed under the Habitats Regulations 2010 and the Infrastructure Act 2015 under which authorities can take enforcement action.

It is vital to check the presence of Japanese knotweed when you are purchasing a property as failure to do so could mean its presence could cause significant problems and failure to maintain its growth could result in severe penalties being incurred.

To speak with a member of our team on any property or property litigation issue you can contact partner, Shilpa Mathuradas, who is recommended in the Legal 500. Shilpa can be contacted on 020 7485 8811 or by e-mailing shilpamathuradas@osbornes.net.