Frequently Asked Questions

Got questions? Get answers here.

And if you need anything else, you know who to call.

How do I know if I have Japanese Knotweed present on my land or property?

The simple answer is to just email us a photograph of what you think is the offending plant, and we will be more than happy to give you our professional opinion.

Please feel free to email a close up picture to

Is it illegal to have Japanese Knotweed on your land?

There are many laws that govern Japanese Knotweed, but the simple answer is that it is not illegal to have Japanese Knotweed on your land.

Where it becomes a problem is when Japanese Knotweed is allowed to spread onto neighboring land for which the landowner can pursue a civil nuisance claim through the courts.

Additionally, you can be prosecuted in the magistrates’ court and may be committing a criminal offence if you allow Japanese Knotweed to grow in the wild.

Is Japanese Knotweed expensive to treat?

The eradication of Japanese Knotweed is typically achieved over 3 growing seasons with a further 2 years monitoring.

Multiple site visits are required to administer herbicides through each respective growing season which makes the process labour intensive.

At Inspectas we offer interest free payments to help deal with the problem and offer a price promise to ensure we remain competitive.

What damage can Japanese Knotweed cause?

Japanese Knotweed has the potential to damage buildings and structures if left unattended.

The rhizomes can cause problems to drainage systems, sewers and can potentially block the system resulting in expensive repair bills.

The plant can also cause damage to hard surfaces such as asphalt, driveways and patio areas by exploiting any weakness to push through a new plant.

I’m looking to sell a house with Japanese Knotweed in my garden. What advice would you give?

A property with Japanese Knotweed doesn’t have to be as problematic as you might think.

Providing you employ a reputable contractor to eradicate the problem and ensure that the eradication programme comes with a 10-year guarantee then there should be no reason for a bank or building society to refuse a mortgage against your property.

Be honest and upfront with any potential buyer.  We are more than happy to speak with all parties involved in the sale of your property to talk them through the process and give appropriate constructive advice.

I’m looking to buy a house with Japanese Knotweed in the garden. Should I avoid it at all costs?

Not at all.  The presence of Japanese Knotweed should not deter you from buying a property providing a suitable eradication programme is in place.

Make sure to check the management plan that should have been issued as part of the programme and submit this to your mortgage provider for acceptance.

If no plan is in place get in touch and we will be happy to conduct a full site survey and put forward a suitable eradication programme to carry out the works.

My neighbor has Japanese Knotweed on their property. What can I do?

This is one of the most difficult areas to address as it is not always easy to prove the origin of the infestation.  To be able to bring a civil case against a neighboring property owner the courts will be looking for an opinion based upon the balance of probabilities.

Inspectas can provide a site survey that can address this issue and can also look to talk with any neighboring property owners to help them understand the problem.

Will a bank or building society lend on a property with Japanese Knotweed?

Providing a suitable eradication programme is in place with a 10-year warranty then there should be no reason for a mortgage provider to refuse to lend against the property.

We have been dealing with many mortgage providers and are happy to offer our expert advice to your lender to help secure finance on any property.

What measures can I take to stop Japanese Knotweed from spreading or encroaching onto my property?

The simple answer is to leave it alone and call in professional experts who can deal with the problem for you.  As it only takes a fingernail sized piece of rhizome to develop a new infestation, it really is best to leave the problem to the experts.

Contact us at 0808 168 9335 or email

Tracking the spread of Japanese Knotweed

Where is Japanese Knotweed most prevalent in the UK?

The PlantTracker project is a collaboration between the Environment Agency, Scottish Natural Heritage, the Scottish Environment Protection Agency & Natural Resources Wales.  It is part of the Nature Locator programme which is a collection of projects crowd-sourcing data on biodiversity using smartphone apps and accompanying websites.

Thanks to them, the public can get an oversight of where Japanese Knotweed can be found in the UK – almost in realtime. Check it out here.

For any invasive weed & Japanese Knotweed questions …

… call us FREE on 0800 288 4967 or email

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