Japanese Knotweed Advice | Green Leaf Remediation

Do’s and Dont’s – Knotweed Advice

What To Do and Don’t Do If You Think You Have Knotweed – Advice from Green Leaf Remediation Services

It’s often a very worrying time if you think you could have Japanese Knotweed at your home or business as its reputation of growing out of control and taking over exceeds it. The first thing to do is not to panic as it can be treated and managed in both the short and long term by a Knotweed Specialist like ourselves. We will identify if it is and give you our Knotweed advice on the best and most suitable treatment and management options.

Knotweed Advice & Facts

ALWAYS contact a Knotweed specialist to come out and identify if it is actually Knotweed. They will advise you of the best treatment and control method for your circumstances, property or site.

If you think you may have Knotweed DON’T ignore it or think it will just go away. The above the ground canes die off in Winter, however, this doesn’t mean it has gone, it will be growing and spreading rapidly underground and will remerge again in Springtime.

During its peak growing season (late spring into summer), it CAN grow up to 10cm a day and will quickly grow out of control if it isn’t not treated by a qualified Japanese Knotweed specialist.

It WON’T grow through solid brick, concrete, pipework and foundations and destabilise a structure.

It WILL grow through unstable structures, foundations, pipework or concrete with existing cracks.

It CAN cause subsidence if there are weaknesses in any foundations or structures as the fast-growing strong roots of the weed can cause extensive ground movement, resulting in soil shifting. It is, however, a myth that it can grow through solid concrete.

It ISN’T harmful to animals or people. If you have grazing animals, Knotweed can be safely eaten by sheep, cattle, horses, and goats.

Do NOT use chemicals on an infestation of Knotweed. You have to use the right chemicals to make an impact and you MUST be registered and qualified to do this. If the chemicals run into a waterway and pollute an area you will be liable and could be prosecuted for it.

You should NOT cut Japanese knotweed back as it will spread quickly and widely.

You should NOT dig it up as it will spread to the areas around the original infestation and further afield.

Disturbing Japanese Knotweed WILL help it to spread and this will make it more difficult and costly to manage.


Allowing it to spread is an offence under the legislation that covers Japanese Knotweed:

Section 14(2) of the Wildlife & Countryside Act 1981 (WCA 1981) – Japanese Knotweed Legislation

States that “if any person plants or otherwise cause to grow any plant which is included in part II of schedule 9 in the wild, he shall be guilty of an offence” (JK is one of the plants listed in the schedule). Anyone convicted of an offence under S.14 of the WCA 1981 may face a fine of £5,000 and/or 6 months imprisonment, or 2 years and/or an unlimited fine on indictment.

The Environmental Protection Act 1990 (EPA 1990) – Japanese Knotweed – Controlled Waste Legislation

Contains a number of legal provisions concerning “controlled waste”, which are set out in part II. Any Japanese Knotweed contaminated soil or plant material that you discard, intend to discard or are required to discard is likely to be classified as controlled waste. In simple terms, it has strict disposal conditions and must be taken to a landfill site designated by the local authority for the area and would require special waste transfer documentation, meaning the ‘carrier’ is required to be in possession of a ‘waste transfer license’. It can not be discarded in conventional green recycling bins.

The Hazardous Waste Regulations 2005 (HWR 2005) – Japanese Knotweed – Hazardous Waste Legislation

Similar to the EPA 1990, whilst ‘untreated’ Japanese Knotweed is not considered as Hazardous Waste, any Japanese Knotweed which has been treated with certain herbicides will likely require certain documentation which should contain details about the hazardous properties and any special handling requirements.

The Control of Pesticides Regulations 1986 – Pesticide Legislation

Require any person who uses a pesticide to take all reasonable precautions to protect the health of human beings, creatures & plants, safeguard the environment and in particular avoid the pollution of water. For the application of pesticides in or near water, approval from the Environment Agency should be sought before use.


Requires any person to take ‘reasonable action’ to contain any plant on their land and recommends that landowners work in co-operation with neighbours whilst retaining a careful record of management. Taking ‘reasonable steps’ (such as control action) to contain any plants is highly likely to provide landowners with clear evidence in the event of any criminal or civil proceedings.

National Infrastructure Act 2015 – Invasive Non-Native Species Legislation

Introduces much-needed powers to control invasive non-native species in England & Wales. The measures provide government agencies in England and Wales with powers to enter into control agreements and, if necessary control orders with landowners to ensure action can be taken against harmful species on their land.

Selling a Property With Knotweed 

The Law Society’s TA6 property information form requires sellers to state whether the property is affected by Japanese knotweed. If you answer untruthfully, your buyer can come back to you and either rescind the contract or claim damages from you. We have personally been involved in several disputes, whereby a property has been sold and the previous owner has deliberately concealed any physical evidence of Japanese Knotweed on the property and have clearly lied on the TA6 form. In all cases, the new owners have sought redress.

Removing Japanese Knotweed

Knotweed AdviceRemoving Japanese Knotweed yourself can be possible, however, it is extremely difficult to do it in a way that prevents it from spreading. More often than not doing it without a Japanese Knotweed specialist and without using the right herbicide treatments will result in it almost always growing back and spreading further over and underground, which you will be liable for if it spreads into the wild or onto neighbouring land or property.

Approved herbicides need a qualified specialist to use safely and effectively and it can take a couple of years to effectively treat and control Japanese knotweed to ensure the underground rhizomes become dormant. There are ways that Knotweed can be removed immediately, however, there is a huge amount of legislation around these processes and you should always use a qualified Japanese Knotweed specialist to undertake them. Knotweed is classified as “controlled waste” under the Environmental Protection Act 1990, and this means it has to be meticulously removed and taken to a licensed landfill site by a qualified specialist.

If Japanese Knotweed is allowed to spread onto someone’s land or property private nuisance proceedings can be issued in the Civil Courts for:

    • damages for loss of enjoyment and diminution of value of a property
    • the costs of removal
    • an injunction against re-infestation

Local Authorities can serve notice on an occupier of land which has Japanese Knotweed growing. It instructs the landowner to treat and manage the knotweed within a set timescale if it is adversely affecting an area. If this is not actioned or the Knotweed is not safely and properly disposed of it can lead to criminal action being taken.

When Japanese knotweed is identified on a property, mortgage providers will nearly always refuse to lend on the property if there is not a specialist knotweed management plan (JKMP) in place as it is deemed as too much of a risk to lenders. A JKMP with Insurance Backed Guarantees cover you if the Knotweed returns and stays with the property when it is sold and this is why some mortgage companies will accept and lend on a property.


If you think you might have Japanese Knotweed it is your legal responsibility to control it. Contact Green Leaf Remediation Specialists on 01269 591651 or 07531 142316. We will answer any questions you have and can arrange for a free site survey anywhere in Wales, the South West, the West Country, as far North as Shropshire and into the Midlands & Birmingham areas.

We are a fully qualified Japanese Knotweed Certificated Surveyor (JKCS) and we specialise in controlling, treating and removing Japanese Knotweed for domestic or commercial properties, private or public land and development sites. We also offer services for other invasive plants and ‘general nuisance weeds’ which are found in the UK.

We provide tree services, including pollarding, crowning, pruning, felling, through our NPTC chainsaw operators, who all possess an extensive amount of experience in the forestry industry.

Green Leaf Remediation Qualifications & Accreditations

    • City & Guilds NPTC Level 2
    • Principles of Safe Handling & Application of Pesticides (PA1/PA6)
    • Principles of Safe Handling & Application of Pesticides near water (PA6AW)
    • Herbicide Stem Injection
    • Members of The Property Care Association
    • The Control & Eradication of Japanese Knotweed Surveyor’s Training Course
    • Qualified Technician (PCAQT) in Japanese Knotweed
    • Accredited Surveyor in Japanese Knotweed

We can identify if you have Japanese knotweed and give you advice on the best and most effective method of treatment and removal for your property and circumstances. There are varying methods of removing and controlling Japanese Knotweed and we will give you advice about the best and most effective method for your property.