Japanese knotweed frequently asked questions

Japanese knotweed (scientific name: Fallopia japonica) is perennial plant of the knotweed and buckwheat family.  It is a fast growing plant with broad leaves, bamboo like stems and pretty white flowers.  Although native to East Asia, it was introduced to Europe in the Victorian era; the Royal Botanic Gardens at Kew received the UK’s first sample in 1850.  Several years later the plant became commercially available and was planted in gardens and found uses around coal pits, along railway embankments and in other areas where its quick developing root system was considered positive.

You are not legally required to employ a specialist Japanese knotweed management or removal company to deal with your Japanese knotweed infestation.  However, Section 33 (1)(c) of the Environmental Protection Act 1990 lays out stringent rules for the disposal of controlled waste that include removed extracts of the Japanese knotweed plant.  Should an individual fail to follow the correct procedures for the disposal of the removed plant they would be liable for legal action.

As most mortgage providers insist upon an insurance backed guarantee for services relating to the removal of Japanese knotweed, it is advisable to use a professional service if you have an immediate need to deal with the plant. Measures taken by a private individual are unlikely to satisfy a lender or purchaser.

It’s not illegal to have Japanese knotweed on your land, however under section 14(2) of the Wildlife and Countryside Act 1981 it is an offence if any person plants or otherwise causes to grow Japanese knotweed, or any hybrid of it, in the wild.  Amendments to this act by the Countryside and Rights of Way Act 2000 for England and Wales, allow a Magistrates or County Court to impose a fine, prison sentence, or both to any person(s) deemed to have not “taken all reasonable steps and exercised all due diligence to avoid committing the offence”.

In the first instance it is best to talk with your neighbour, most people are unaware about the destructive nature of the plant, about how easily it spreads and the associated problems.  There are plenty of resources online, including our site, that will provide your neighbour with the information needed to decide upon next steps.

Should the weed spread to your land and your neighbour decides not to act, then your legal remedy in England and Wales would be under private nuisance.  This is an area of tort law that comes into force where the actions of defendant are “causing a substantial and unreasonable interference with a [claimant]’s land or his use or enjoyment of that land”.

Legally there is nothing to stop a person from trying to sell a property that has Japanese knotweed present.  However, during the conveyance process the seller’s solicitor should send a TA6 Law Society form asking whether Japanese knotweed affects the property.  If the answer is yes, the next question will be whether a Japanese knotweed management plan is in place, and if so the seller will be required to provide it.

An Estate Agent advising on the purchase of a property is obliged to notify prospective purchasers of any material facts that affect the consumer’s decision to purchase and Japanese knotweed is counted as such a factor.  In order for either a seller or purchaser to deal with the issue it is necessary for them to be transparent and take the necessary measures to eradicate the weed.

An insurance backed guarantee gives the consumer peace of mind that in the event a company ceases trading, claims under the original guarantee will be honoured for the remainder of the quoted guarantee period.

Mortgage providers often require an insurance backed guarantee on properties that have a Japanese knotweed infestation before providing the lender with a mortgage.

Japanese Knotweed Management is a Surrey based company that provides a service to the UK and Ireland.  We can normally establish if Japanese knotweed is growing on your property from photographs supplied, however we would undertake a site visit to establish the extent of the infestation and to discuss the remedies available.

The treatment or removal method for Japanese knotweed depends on the level of infestation and needs of the property owner/client.

A specially formulated herbicide can be sprayed on large areas that will inhibit the plant’s ability to produce three essential amino acids necessary for it to synthesize.  The herbicide is particularly suited to flat, fast growing broad-leaved plants like Japanese knotweed and Giant hogweed as it is absorbed easily through foliage.  A number of applications are likely to be needed to ensure that growth of the plant is halted.

For a more targeted approach, a stem injection process can be used that will ensure that the herbicide directly targets the plant without affecting plants within close proximity.

Landowners and property developers requiring a quick solution to the problem often select a removal process that involves digging out the rhizome (or root).  Contaminated soil is removed and either transported to an authorised landfill, or buried on-site in a process that requires the excavated earth to be buried at least 5 metres below ground.  There are variants on these methods for sites that do not have the necessary capacity for the burial of contaminated materials.

Another method, common with commercial landowners that require a quick solution, involves the introduction of a vertical root barrier or membrane.  This is often used on sites that have previously had a Japanese knotweed infestation and are now taking thorough precautionary steps to prevent the re-emergence of the plant.

Whilst it is widely known that the plant establishes itself quickly, this is due to dispersal of the rhizome (root), or sections of the stem.  Part of the reason that Japanese knotweed has become such a problem is because even a very small section can establish itself very easily.  In the Victorian era cuttings were widely exchanged which assisted its spread, however as it is now not advised to plant the species or encourage growth, new patches are largely accidental.

In the summer months the plant will flower, but it will not seed.  All plants in the United Kingdom are derived from a female specimen; therefore seeds will not be produced and are consequently not a contributing factor in dispersion.