Japanese knotweed

Japanese knotweed (JKW) is a plant that can grow and spread quickly from Spring to Autumn. During the Winter months, the plant dies back leaving dead bamboo-like stems exposed. It emerges from its roots called rhizomes to grow to over 2m tall. Successful eradication takes several years requires with chemicals treatment being the most successful. Recent changes in legislation covers its control.

What is Japanese knotweed?

European adventurer Philipp Franz von Siebold is documented as transporting JKW from a Japanese volcano to Leiden in the Netherlands. In 1850, a specimen from this plant was donated by Von Siebold to the Royal Botanic Gardens, at Kew.

Commonly known as Japanese knotweed or Fallopia Japonica, has a bamboo like green / red coloured stem with large green heart shaped leaves. Starting in the Spring Japanese knotweed grows very quickly, flowers (inflorescence) July / August and drops leaves (senecence) in September / October. Above ground it fully dies back over the winter. They can remain dormant for several months or longer. The Rhizomes (roots) lie dormant until the following year or for many years. The creamy-white flowers produced in late summer and early autumn fortunately cannot pollinate which is great news in regards its control.

What is the problem?

Japanese knotweed can regenerate from very small sections of leaf, stem or rhizomes. I have been to a job were the customer had used a strimmer to try and kill some Japanese knotweed. Unfortunately for him it was able to regenerate from most of the mess he had caused.

The Legal standing.

Under the provisions made within Schedule 9 of the Wildlife and Countryside Act 1981, it is an offence to cause Japanese knotweed to grow in the wild. Even pulling up shoots or stems and putting them in your council green waste bin is an offence!

Fly tipping should be reported to The Environment Agency, free-phone number 0800 807060.

Since 2013, the seller of a property is required to state if Japanese knotweed (Fallopia japonica) is present on their property through a TA6 form – the property information form used for conveyancing. Your conveyancer or solicitor will be able to provide full legal advice.

If you are buying, the presence of Japanese knotweed will be detailed on the TA6 form. This often results in mortgage lenders requiring assurances that it will be eradicated before agreeing the funds. A treatment plan by a Standish Property Maintenance& Pest Control, backed by a transferable guarantee, is usually sufficient. It is most common for this plan to be provided and paid for by the seller before the purchase is completed.

The lack of a treatment plan can result in delays, increased costs later in the buying process, or even a possible misrepresentation claim after the sale, so a proactive approach to the infestation will help avoid problems.

New legislation

An amendment to the ‘Anti-Social Behaviour, Crime and Policing Act 2014’ includes invasive non-native plants such as Japanese knotweed. It is not illegal to have Japanese knotweed in your garden. However, you should aim to control this invasive non-native plant to prevent it becoming a problem for your neighbours. If it has a “detrimental effect of a persistent or continuing nature on the quality of life of those in the locality”, the legislation could be used to enforce its control and property owners may be prosecuted.

When Japanese knotweed infestations occurring on property boarders, we would always suggest that you speak with your neighbours. They may already be taking action to control the Japanese knotweed. An informal approach usually helps ease the tension of what can be for some a worrying problem. If this fails to work contacting your council to talk about action under the legislation would be the next step.

You could consider control yourself for a small, isolated infestation. However, Standish Property Maintenance & Pest Control are skilled and experienced at control, ensure eradication and can advise you on how best to tackle your problem.

For more information see The Environment Agency Information Note: Japanese knotweed Control

Non-chemical control

Digging out Japanese knotweed without professional help, creates problems over disposal. Japanese knotweed has been classed as ‘controlled waste’ under the Environmental Protection Act 1990. Requiring disposal at licensed landfill sites. Registered waste carriers must be used to safely remove the weed from site.

On no account should Japanese knotweed be included with normal household waste or put out in green waste collection schemes.

Weedkiller control

It usually takes at least three to four seasons to eradicate JKW using high strength herbicide. At Standish Property Maintenance & Pest Control we have access to Professional Grade Herbicides that may reduce this period. The product label will state the use is for Japanese Knotweed. Situation dependant we either spray wipe or stem inject a high concentrate of Glyphosate to eradicate the whole plant.

In a few cases resilient sections of rhizome may continue to produce some leaf growth known as leaf rosettes. Mop up treatments must be carried out on these to prevent further infestations. They are very different in appearance to the normal plant and it is essential that this regrowth is treated.

Bear in mind that the home gardener will not get an insurance backed guarantee without using a professional company for the control of Japanese knotweed. This may be important if planning to sell your property in the near future or if a neighbour is threatening litigation from the spread of knotweed from your property. It is often less expensive than most people worry about as documented in the press.

If you have any questions, queries or concerns please don’t hesitate to contact us for help or advice. Its always quickest to call us on 07920001980, but if you have a lot to ask or require some detail use our ‘contact‘page.