Just send us a photograph of what you think is the offending plant, and we will be more than happy to give you our professional opinion. See our free identification service at the bottom of the page.

If we are unsure, or identify Japanese Knotweed, we would recommend a site survey to be conducted by PCA qualified professionals, such as ourselves.

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. Check it out here.

Effects on my property. Damage, Sale & Purchase.

There are multiple ways in which the plant is spread:

  • Animals such as foxes or badgers could carry a small piece of the rhizome (underground stem of the plant that stores nutrients) on their fur into your garden resulting in regrowth.
  • Streams, waterways, railway lines next to your property can act as channels for growth.
  • Fly tipping, use of contaminated soil. Rhizome fragments as small as 0.8 gram or stem fragments with two nodes are capable of regeneration into new plants.
  • Growth from a neighbouring property.

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.

It is the responsibility of the vendor to report Japanese Knotweed on the TA6 form if they know they have it. If it is found later and the vendor has tried to hide it there can be serious consequences.

In most cases a conveyance surveyor will identify it as part of their survey report, they tend to air on the side of caution. So, even if they are not sure they will still insist that a Japanese Knotweed specialist visit the site and provide a survey report. This specialist survey should be completed by PCA qualified providers like Japanese Knotweed Services. Link to request a survey Always opt for a company that has PCA-qualified surveyors and they will be able to provide you with all the paperwork necessary to ensure a smooth sale of your property.

There is no need to wait for a surveyor to check, you can send us an image and we will help you identify if you have Japanese Knotweed, free of charge.

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.

A qualified surveyor who is a member of the RICS can assess the impact of Knotweed infestation on value of the property.

Not at all.  The presence of Japanese Knotweed should not deter you from purchasing a property, or land, providing a suitable treatment 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.

In order to satisfy the lender of the mortgage, a survey will need to be conducted by PCA qualified surveyors, followed by treatment, a management plan and where possible 10-year independent insurance backed guarantee.

If all these things are put into place, in most cases, mortgage lenders will lend money against the property.

We recommend that you undertake a Japanese Knotweed survey, using PCA qualified operatives, to establish if you do have knotweed and to understand treatment that will be required.  With such a survey, our experts would offer specific advice on your options going forward.


If your neighbour has Japanese knotweed, then you should tell them as soon as possible. It is important they understand the damage that this invasive species causes and encourage them to get professionals in to carry out a treatment programme.  It may be in your interests to offer to share costs involved.

Options are available if the normal neighbourly channels of communication fail. 

  • If Knotweed has spread to your property and damage has already occurred, your insurance company may be willing to get involved.
  • You may be entitled to legal advice through your property insurance policy.
  • You could take legal advice to see if there a course for legal redress.

If a conveyancing surveyor has highlighted Japanese Knotweed on a neighbour’s land that could impact on the sale of your property, you will need a management plan in place in order to sell the property.

The sensible option is to discuss this with your neighbour where possible. In some cases, they will pay for the treatment, or at least contribute towards the cost. If they refuse and you are left to pay for it, you could seek legal advice to see if anything could be done.

The law is a little grey in this area, potentially they are obstructing the sale of your property. We recommend you seek legal advice.


When selling your property, you are required under section 7.8 of the TA6 property questionnaire to declare if you know that Japanese Knotweed is present.

If Japanese Knotweed is allowed to spread onto neighbouring land, the landowner can pursue a civil nuisance claim through the courts.

You can be prosecuted in the magistrates’ court and may be committing a criminal offence if you allow Japanese Knotweed to spread from your property and grow in the wild.

If you knowingly let Japanese Knotweed spread onto neighbours land, you could be considered a nuisance and, after being warned about this, an ASBO is an option available to the authorities.

We would not recommend this as it will only serve to spread the Knotweed and could well reduce the options for treatment on your property.

Disposing of the plant of ‘common’ ground may be considered as spreading the plant. According to the Wildlife and Countryside Act 1981, if any person plants or otherwise cause to grow in the wild any plant which is included in Part II of Schedule 9, such as Japanese Knotweed, the person may face a fine of £5,000 and/or 6 months imprisonment, or 2 years and/or an unlimited fine on indictment.

Treatment and Disposal

Digging out and sifting soil contaminated with Japanese Knotweed will always carry a risk of regrowth on-site or spread to other sites through machinery and footwear. In contrast, applying chemical treatment minimises spread of the plant off-site.

In some instances, digging out can be the only option. Herbicide treatment normally takes 2-3 years followed by 2-year monitoring to eradicate the plant, whereas digging can be undertaken within a short period of time. The time factor could be crucial for construction companies. For most of the domestic and other customers who do not require site development, herbicide treatment is an ideal cost-effective alternative.

We normally apply a two year treatment course using herbicides to kill the Knotweed. This is followed by a two-year monitoring period to ensure that the probability of regrowth in the future will be low. The herbicide is sprayed onto the leaves or injected into the stems and so enough growth is needed for this to be effective. The chemical is drawn down into the plant’s vascular system and halts the production of amino acids, which build up the protein that the plant needs to grow and survive. The plant will effectively slowly starve to death. If the plant is well established and densely populates the area, a treatment course may be extended to three years.

Japanese Knotweed could turn to a dormant state for up to 10 years if the wrong herbicide or wrong dose of herbicide is applied. We do not recommend using strong weed killers from your local DIY store due to this risk. The use of other substances such as diesel, petrol, vinegar, white spirits, etc. must be avoided due to the risk of contamination of soil, plus they will not kill the Knotweed.

It is always advised to refer to specialist companies that are qualified to use professional grade herbicides and have a license to handle and apply them and produce a management plan. A mortgage lender will not lend on a property where Japanese Knotweed has been treated without the production of a management plan.

Grandfather Rules exemption is no longer allowed since 26th November 2015. Formally,  if you were born before 31 December 1964, you were allowed to apply professional pesticides on your land (Grandfather Rules). Since 26th November 2015 this is no longer the case, you are required hold a recognised certificate.

We absolutely do not recommend this, however some people do try to hide Japanese Knotweed, there are weed membranes available that will do a good job of this. However, over time it will find a way out and start to spread.

It is a legal requirement to report Japanese Knotweed when you come to sell your property.

You must prevent spreading the plant, or soil contaminated with the plant fragments, outside of your property boundary.

You can compost or burn (if permitted) on your land.

You must not put the plant/contaminated soil in the bin for general/garden waste.

You can arrange disposal of the Knotweed off-site. However, as it is classed as a controlled waste, the transportation must be undertaken by a dedicated waste carrier to a licensed landfill site and accompanied by the appropriate waste transfer documentation.

The treatment is normally applied when the plant is at least three feet high. It should have sufficient foliage area to absorb enough herbicide to be translocated to the rhizome system if applied by spraying. If the injection method is preferable, the stem thickness should be 1 cm or over. Normally, the first treatment may be applied at the end of June to the beginning of July, with the second treatment in September, or up to the beginning of October in mild weather conditions.

Treatment by spraying cannot be applied in wet weather conditions. The plant needs to be sprayed at least two hours after the rain has stopped and at least half an hour before more rain is expected.

Injection of the herbicide can potentially be carried out in any weather condition. However, after prolonged raining, the bottom of the stems (where the injection is applied) may be filled with water that may reduce treatment efficiency. Therefore, a couple of days after prolonged rain should be allowed for efficient treatment by injection.


The plant is not harmful to you or your pets. In some cultures, the plant is actually used for medicinal purposes. Various Knotweed recipes, including Japanese Knotweed wine, are available online. If you are cooking Japanese Knotweed in your house, the plant fragments must be taken from your land only. Otherwise, it may be considered as an attempt to spread the plant, with possible legal consequences.

In some areas of Scotland, the plant is protected as it shelters otters while they are migrating between different wet areas.

The herbicide we use it is not classified as dangerous.

It is not expected to produce significant adverse effects to the environment when recommended usage instructions are followed.

It is not a persistent, bioaccumulative or toxic nor a very persistent, very bioaccumulative mixture.

Short-term eye contact, skin contact, inhalation is not expected to produce significant adverse effects when following the recommended usage instructions. However, it is advised to avoid all of these by using the appropriate safety equipment.

It is not harmful to pets. It is recommended to keep pets inside during the treatment until herbicide has dried to stop them bringing wet herbicide to plants that are not intended to be treated.

If anyone sprays herbicide close to your house, we recommend you shut your doors and windows, keeping pets inside to avoid any unknown issues that may be caused by treatment.

‘Free’ identification service just ask our experts:

If you are still unsure if you have Japanese Knotweed then please click here and upload a photo of the plant in question and one of our experts will feedback to you within 24hrs. If you have any questions then one of the team will be happy to help just call 01782 901074 or 07818 414900 for a free consultation.