Japanese knotweed is a highly invasive weed that can cause serious damage to property.
If you’re selling a property and discover Japanese knotweed on the land, it can be a huge problem. The weed can quickly take over an area, damaging fences, walls, and even foundations in the process.
If you find Japanese knotweed on a property, don’t panic. There are things you can do to mitigate the damage and get rid of the weed. Our guide will walk you through the steps you need to take to deal with this pesky plant.
Do sellers have to disclose Japanese knotweed?
Japanese knotweed (Reynoutria japonica) is a fast-growing perennial plant that can cause serious damage to buildings and flood defences.
The plant was introduced to the UK in the 19th century as an ornamental plant, but it quickly spread into the wild, where it now poses a significant threat to our natural environment.
Knotweed can grow up to 3m high and its roots can extend up to 7m deep, making it extremely difficult to remove.
The plant is also very destructive, as its roots can break through concrete, tarmac and brickwork that has cracks and fissures to be exploited.
Knotweed is particularly problematic in flood-prone areas, as its large root system can destabilise river banks and increase the risk of flooding.
In recent years, there has been a lot of media coverage on the issue of knotweed, with some sellers going so far as to disclose its presence on their property before putting it up for sale.
Knotweed is classed as ‘controlled waste’ under the Environmental Protection Act 1990, which means that it must be disposed of at a licensed landfill site.
However, knotweed does not have to be disclosed by sellers if they are not aware of its presence on their property.

Can I sell my house if my neighbour has Japanese knotweed?
Japanese knotweed is a fast-growing and invasive plant that can cause extensive damage to both property and infrastructure. If left unchecked, knotweed can spread rapidly, choking out native plants and causing structural damage to buildings.
As a result, it is considered to be one of the most damaging invasive species in the UK. If you have knotweed on your property or it is next to your boundary from neighbours, it can be difficult to sell your house.
This is because knotweed is classed as “controlled waste” under the Environmental Protection Act 1990, and it is illegal to dispose of knotweed in a way that could cause it to spread.
As a result, potential buyers may be put off by the extra costs associated with removing knotweed from a property. If you do have knotweed on your property, it’s important to get professional help to deal with it before trying to sell your house.
Is it a criminal offence to sell a property with Japanese knotweed?
It is not illegal to sell a property with Japanese knotweed on it. However, knowing it is there and not declaring it to the future buyer can cause many issues.
Knotweed can grow up to three feet in a single month, and its roots can extend 20 feet underground. knotweed is also very difficult to kill; even small fragments of the plant can regrow into a full-fledged knotweed patch. knotweed is so destructive that it is often referred to as “the plant that ate the mortgage.”
Because of the plant’s destructive nature, it is considered a controlled substance in many countries, and it is illegal to sell property with knotweed without disclosing its presence.
In the United Kingdom, for example, failure to disclose knotweed can result in a fine of up to £5,000.
As a result, if you are selling property with knotweed, it is essential, to be honest about its presence and take steps to remove it from the property. Taking these measures will help to protect both the buyer and the seller from potential financial damages.
If you suspect that your property may be infected with knotweed, it is important to seek professional advice as soon as possible.

How much does knotweed devalue a house?
Knotweed is a common problem in the UK, with an estimated 1.25 million properties affected by the invasive plant.
Knotweed can cause serious damage to buildings, with the roots able to grow through concrete and brickwork.
As a result, knotweed can devalue a property by up to 10% and in some cases, knotweed can also make a property unsellable.
If you suspect that knotweed is present on your property, it is important to seek professional help as soon as possible and if left untreated, knotweed can spread quickly and cause significant damage. With early intervention, however, knotweed can be controlled and the value of your property preserved.
Tips for selling a property with Japanese knotweed
Japanese knotweed is an invasive plant species that can cause serious damage to property. If you have knotweed on your property, it’s important to take steps to remove it before listing your property for sale.
Here is a list of things you should do if you discover Japanese knotweed on a property:
1) Contact a professional immediately. Knotweed can be very difficult to eradicate, so it’s important to hire a professional removal company.
2) Don’t try to remove the weed yourself unless you are well-prepared and have the necessary weedkillers.
3) Keep people and animals away from the area so that you do not end up spreading it beyond the infected area.
4) You should also disclose the presence of knotweed to potential buyers and provide them with information about the removal process.
5) With knotweed, knowledge is power, so arm yourself with information and take action to sell your property knotweed-free.
In conclusion
The plant is extremely difficult to remove, and its presence can devalue a property. As a result, knotweed can make it difficult to sell a house. If you have knotweed on your property, it is important to get professional help to remove it. Otherwise, you may find it difficult to sell your house in the future.
Ultimately, understanding the problem and knowing how best to tackle it is your best course of action.
Want to know more about Japanese knotweed?
Knotweed Removal aims to provide the most up-to-date information, help, and advice for YOU to make informed decisions. If you are unsure or uncertain about how to proceed, please reach out to us and we will gladly come back and advise you as best we can.
Governmental advice can be found here and the UK law covering the removal of Japanese Knotweed as stated under the Wildlife and Countryside Act 1981 can be found here.
The best means to contact us is via our email – hello@knotweedremoval.tips
Do not forget we have a library of blogs covering many areas relevant to Japanese Knotweed, our free downloadable How-to Guides, and Product Reviews on the latest methods being employed to eradicate or remove Japanese Knotweed.
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