Japanese Knotweed Thornbury Treatment and Control

  1. Do you think you may have Japanese Knotweed Thornbury?
  2. Have you read online how this is going to set you back £1,000’s?
  3. Have you been told how it could impact your mortgage or ability to sell your house?

Please do not worry! South West Knotweed Removal offers solutions for the treatment method and control of Knotweed in Thornbury and the surrounding areas, and be assured it doesn’t cost as much as you might think. Contact us today on either 0117 321 7799 or 07531142316 and we can answer any questions you may have.


Japanese Knotweed is a perennial weed that grows and propagates really quickly if not treated and managed by a Knotweed expert. It is a weed that will rapidly suppress other plants growing around and its crown and rhizomes (root system) will spread extensively below the ground without you knowing. Its shoots die off above ground in the winter and re-emerge above ground again at the end of spring, early summer so many people think they have got rid of it or it has died but unfortunately unless it is treated properly it will re-emerge and normally in a larger area.

Any well-established shoots can grow in excess of 9ft high and can colonize the soil within a few years or sometimes months. There are many articles that say you can eliminate the roots with chemicals yourself, however, you will need an NPTC qualified person to utilise any chemicals due to new legislation which covers the management, and removal of Knotweed.

There are plenty of myths that say you can remove Knotweed manually yourself, however, this is an extremely hard and intricate process and in most cases, not successful unless you employ a Knotweed specialist like South West Knotweed who has the qualifications and experience.

At the peak of its growing season, 60% of the Knotweed weeds roots are underground so removal is extremely difficult as well as spreading wildly from one tiny fragment of crown or rhizome. Removing Knotweed without having substantial knowledge has a very good probability of spreading the plant to other regions of the soil that have been previously unaffected.


How do you eradicate Knotweed Thornbury?

There are recognised methods of getting rid of Knotweed and a Knotweed Professional like South West Knotweed Removal will be able to give you advice about the best and most effective procedure for your land or property.

Knotweed Thornbury Stem-Injection

This is a low impact approach to removal and there is little potential for disturbing or killing the plants and flowers growing about it. The stem injection method is normally used for smaller sized areas of Knotweed where it has established itself amongst plants and vegetation that you would like to keep. It is also a method normally used when Knotweed is close to a watercourse as there is minimal risk of the chemicals running into the water causing pollution. The stem-injection process must be used in dry or inclement weather conditions and the soil cannot be disturbed following a treatment. The stems of the Knotweed need to be thick enough to inject enough herbicide into them and a specialist will advise you on this.

Knotweed Thornbury Foliar Spray Application

This method is often used and is one of the most favourable control methods along with stem injection. It is used to treat the Knotweed over a number of growing seasons. Dependent upon how large the area of Knotweed is it is frequently sprayed 2-3 times in the first year and once in the subsequent year. The chemical used is an Environment Agency approved herbicide and requires dry weather conditions and the soil to remain undisturbed in subsequent years to be effective.

Knotweed Thornbury Weed Wiping Method

This method is where the leaves of the plant are wiped with a sponge which is soaked with the necessary herbicide. This is a low impact treatment and doesn’t kill or bother the foliage surrounding it, nonetheless, its use depends upon the size of the area of knotweed as it is not suitable for large areas. The method can be used close to a watercourse and the leaves need to be visible and big enough to be wiped effectively.

Knotweed Thornbury Bund/Stockpiling Method

This is a combined treatment using stem injection or foliar application, which is then followed by excavating the underground material and removing it to a different location on site where the emergence of ‘new shoots’ can be subjected to further herbicide application. This method is used on sites where you need the removal of the knotweed to be quick and not done over several seasons so is specifically beneficial to building and development sites as work can carry on at once.

Knotweed Thornbury Cell Burial/Root Barrier Method

This treatment is used if you have enough space on-site to create a cell burial or you are able to make use of a root barrier to prevent the considerable expenses of transporting the soil and waste to landfill. Cell burial buries the Knotweed waste to a minimum depth, or if encapsulated inside a geomembrane it can be closer to the surface of the ground. Root barriers can be installed both vertically and horizontally when there is a threat of cross-boundary contamination. Again, it is a method frequently used for development sites when development work needs to start immediately.

Knotweed Thornbury Excavation & Removal Off-Site

This is a legitimate and swift control option that has its advantages for development sites if done correctly, nonetheless, a lot of Knotweeds professionals are not advocates of it because it raises considerable logistical problems. The challenge being there is an extremely high chance of the Knotweed spreading in addition to the cost to safely transport the material to a designated and licensed landfill site. There is also significant duty of care requirements under the Environmental Protection Act (EPA) 1990. In summary Excavation & Removal should only be used as an absolute final option.


Our Japanese Knotweed treatment methods are endorsed by the Environment Agency Codes of Practice and the industry trade body (The Property Care Association) and they are tailored to suit you as the client, and the property or land where the Knotweed is growing. We are happy to consider a staggered payment schedule for any work that does not involve a 3rd party, who may require evidence of pre-payment in full from the outset (mortgage lenders as an example).

As certified Japanese Knotweed Management Plan (JKMP) Surveyors, we provide a detailed document that shows how we as the contractor will use the appropriate methods of treatment bespoke to the property or site to control or remove the Knotweed. They include the severity of the contamination on-site, an evaluation of the control options available, a detailed assessment of the risks associated with any control methods and advice on biosecurity. The JKMP is updated annually following treatment & evaluation.

We provide JKMP’s for residential properties, building plots that are subject to housing development and larger-scale development projects. A JKMP is normally required if you are applying for a mortgage on a property where there is evidence of Japanese Knotweed before an agreement is made to lend the funds for the property purchase.

Our JKMP’s are supplemented with a 10-year Insurance Backed Guarantee (IBG). The JKMP ‘stays’ with the property, so if there is any future property transfer the JKMP becomes the possession of the new owner, irrespective of how many times the property exchanges hands. You can find more information here.


Knotweed Thornbury

Common Japanese Knotweed Myths

It will grow through solid concrete

It will destabilise foundations

It will cause structural damage

Property affected by Japanese Knotweed is not mortgageable

Japanese Knotweed Facts

Essentially, if the previous groundwork or construction is solid then Knotweed is not going to grow through it. It does not destabilise solid foundations and it is highly unlikely to ‘cause’ architectural damage. These claims are deceptive, to say the least, and untrue.

In a few instances, if the foundations or concrete are old and have pre-existing cracks or fractures within them, then Knotweed will unquestionably take advantage of any weak spot in its search for light and water and can swiftly establish itself, whilst exacerbating the initial fracture and possibly cause damage.

South West Knotweed Removal

South West Knotweed Removal Specialists cover the whole of South West including Thornbury and the surrounding areas. We also carry out contracts in 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 a family run business. We specialise in managing Japanese Knotweed, other invasive plant varieties and ‘general nuisance weeds’ that are found in the United Kingdom for residential premises and property development sites.

We also offer tree services, such as pollarding, crowning, pruning, felling, through our NPTC chainsaw operators, all of whom possess a vast amount of practical experience within the forestry industry.

Our 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
    • Property Care Association Members
    • The Control & Eradication of Japanese Knotweed Surveyor’s Training Course
    • Qualified Technician (PCAQT) in Japanese Knotweed
    • Accredited Surveyor in Japanese Knotweed

We always advise anyone to exercise caution and to ensure that the business you use to undertake the control programme is qualified and complies with the industry codes of practice. If you are unsure please contact us on 0117 321 7799 or 07531142316 and one of our experts can answer any questions you may have. We offer free no-obligation site surveys in Thornbury to assess if you have Japanese Knotweed present.

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