Back to Blog Posts

Japanese knotweed

Japanese Knotweed may look like an attractive flower in the summer months, but since it was introduced to the UK in the mid-nineteenth century, it has spread widely to become a pest for many homeowners. It is incredibly invasive, growing and spreading fast through the tiniest of cracks in concrete or brick.

It is something which costs the UK millions of pounds each year to control, as it can be a threat to natural habitat also, as it invades areas where native plants are located and destroys suitable migration areas for animals and wildlife.

For developers or homeowners, Japanese Knotweed poses a real problem as it quickly colonises whole areas of land and should be dealt with as quickly as possible. However, it is known to be resistant to most high street weed-killers and often needs several attempts before it is eradicated completely.

It is possible to use chemicals, by spraying in spring, then applying again in mid-summer and finally at the end of summer as it begins to die down, but then it may take several seasons before it is gone completely. You can also attempt to dig it out, but the roots still need to be treated otherwise it is highly likely to grow back again.

It’s also important to note that Japanese Knotweed is classed as ‘controlled waste’ under the Environmental Protection Act and therefore needs to be disposed of at a regulated landfill site rather than put in with general waste. Other than this, research is on-going with regards to controlling this nationwide infestation and many trials have been carried out over the years to attempt to eradicate the problem.

Japanese Knotweed can be so problematic that many people will be unable to get a mortgage if it comes up on a survey. However it may be possible if a remediation plan is put in place to control it. Every mortgage lender has its own policy, but in some cases it can be a real problem for prospective home owners.

According to Stephen Morgan from the Royal Institution of Chartered Surveyors; they recognise Japanese Knotweed is a problem and that the risk assessment for surveyors can be problematic, so they have now set up a working party involving the Council of Mortgage Lenders to give clearer guidelines regarding Japanese Knotweed. This can then help to clarify matters when applying for a mortgage.

There are also plans for a more consistent approach to controlling or eradicating Japanese Knotweed when it is discovered. As up until recently it has just been a case of trial and error, with many attempts proving unsuccessful. Currently, landowners or homeowners are not obliged by law to remove it unless it poses a problem for neighbouring land or property. However it is an offence to deliberately plant it or cause it to grow in the wild. If you think you may have Japanese Knotweed on your land or in your garden or home then it is important to get advice to deal with it as quickly as possible.

See our other common property problems page.

by Cormac Henderson

National Property Trade is rated 4.90 stars by based on 225 merchant reviews

4.90 / 5 Rating
225 Reviews
Contacted NPT in an emergency. Good offer on house, far above what any other company offered. NPT did everything they said they would in their advertising and in our case slightly more. Thanks
We received an excellent service and would without hesitation recommed National Property Trade
Our sale completed last Friday and I have to say we were very impressed with the whole service we received.