Do you know the risks of Japanese Knotweed?

Last Updated on April 5, 2023 by admin

Japanese Knotweed – two words that are likely to send a shiver down the spine of any homeowner in the UK. Now it’s top of the list when it comes to the most unwanted plants in our gardens! It’s easy to understand why if you consider that Japanese knotweed:

• grows at an alarming rate of up to 20cm a day
• will push its way through walls, paving and tarmac
• left unchecked it can damage the entire structural stability of a home.

It’s estimated that to eradicate this invasive pest from the UK it would take an eye watering £1.5 billion. With this cost unlikely to be met, it’s important to understand the implications. What should you do if your home or holiday home falls foul of Japanese Knotweed?

Your legal responsibility

The first point to state is should the plant appear on your premises, it’s your responsibility to eradicated it. New laws state that landowners can be found liable. Especially if there is proof they knew about an infestation of Japanese knotweed and failed to deal with it properly.

Buying a cottage or selling your own holiday home? Property owners affected by knotweed infestation could be open to a lawsuit if they failed to act. Property insurance cover may also be refused. If the knotweed in your garden were to spread to a neighbour’s property, you could even be given an ASBO under the Anti-Social Behavior Crime and Policing Act 2014.

How to remove Japanese knotweed from your holiday home

With the stakes high, and time very much of the essence, it’s important to remove the plant from your land and ensure it’s eradicated permanently. it is likely that the most cost effective method of dealing with it is to use an established professional. The Property Care Association have members who are Invasive Weed Control specialists. You can search for one in your area here. Checking that the firm provides an insurance backed warranty is crucial. This may involve further inspections over a 12 month period. If selling this gives the legal guarantee that solicitors and conveyancers are looking for to demonstrate the issue is under control. Companies should carry adequate insurance with a reputable insurer, and this should preferably include structural damage cover.

DIY methods of removing Japanese knotweed

Explained below are some of the DIY methods that can be used to remove Japanese Knotweed if you catch it early, Although our recommendation would still be to employ a professioanl to carry out the work for you.

1. Non-chemical controls

Whilst Knotweed can be dug out of the ground, the roots are so deep it will usually grow back. If you are attempting to dig it out remove as much of the root as possible, then repeatedly destroy the regrowth (e.g. by mowing). This will exhaust the energy reserves in the remaining underground parts of the plant, however expect it to take several seasons to disappear entirely.

Also bear in mind that if you are digging out Japanese knotweed then this is classed as “controlled waste’, meaning the remains have to be disposed of in a licensed landfill site under the Environmental Protection Act 1990.

2. Chemical control

You can try a glyphosate-based weed killer which would be available from your local garden centre. This will usually be applied to the foliage of the plant and then passes within the plant to the underground parts and roots. It usually takes at least three to four seasons to eradicate Japanese knotweed, but professional contractors have access to more powerful weed killers and may reduce this period by half.

What about my buildings insurance? 

Damage to your property caused by invasive weeds such as Japanese Knotweed isn’t generally covered under your buildings insurance. As homeowners we all have a duty of care to ensure that our properties are well maintained. This includes controlling the spread of invasive weeds such as Japanese Knotweed. If you are considering buying a holiday home in an area where it’s known to occur we recommend you have the property checked for Japanese Knotweed as part of your buildings survey.

Boshers offer specialist holiday home and property insurance to holiday cottage owners across the country. For more information on our policies have a look around Boshers website. For a quote or to ask any question please give our team a call on 01237 429444.

Photo credit – Japanese Knotweed – phlorum.com – Japanese Knotweed identification