Japanese Knotweed Survey | Green Leaf Remediation

What Does a Japanese Knotweed Survey Include?

A Japanese knotweed survey includes information, considerations, risks, treatment, and management advice. 

Japanese knotweed is a persistently invasive plant species that can cause significant damage to properties and sites if left unchecked. Assessments conducted by a qualified Japanese Knotweed specialist provide valuable insights into the extent of infestation on any given property or site. A site survey covers various aspects, including location, density, and growth patterns, to show how much impact it has had so far and, if not, what growth and effects you can expect if you have a knotweed issue. 

A certified Japanese knotweed assessment’s primary objective includes identifying the areas affected by Japanese knotweed early enough before it causes extensive harm and spreads to the outside of your property boundaries, which is illegal, and you could be prosecuted with legal action being taken. Preventing the further spread of this invasive weed through proper management measures ensures compliance with legal requirements for landowners who could have been found liable due to their negligence in managing this problematic weed species effectively otherwise.

Japanese knotweed survey reports can be completed for commercial and residential properties and development sites. Property developers will often use Japanese knotweed specialists to survey a site and advise them of the level of risk associated with the knotweed presence before they make an offer. If the specialist finds it, they will often be required to create a Japanese knotweed management plan that includes the best possible treatment options.


The first step in addressing the problem involves identifying the presence of knotweed. This requires specialists to look for the suspect plant using the specific features of knotweed, such as heart-shaped leaves, bamboo-like stems, and white or pink frothy flowers that are characteristic of this plant species.

A Japanese knotweed infestation is a pressing issue that requires immediate attention. To address it effectively, a knotweed contractor will conduct an extensive site survey to assess the size and extent of its impact on the local ecosystems. This includes measuring factors such as rhizome spread, and density levels across different sites within affected areas. By gathering accurate data through these methods, experts can develop effective strategies for controlling or eradicating this invasive species.

Site Inspection

The specialist will conduct a comprehensive examination of the entire property, including buildings, boundaries, gardens, and open areas, to detect any signs of Japanese knotweed. This thorough inspection is necessary for identifying affected areas promptly so that appropriate measures can be taken without delay.

Risk Assessment

Assessing the potential impact of Japanese knotweed on both private and public properties, as well as the surrounding ecosystems, requires a thorough risk analysis. This involves considering different factors, such as proximity to buildings, watercourses, or sensitive habitats, that may be affected by this invasive plant infestation and any proposed control methods. By doing so, we can understand all the factors that protect our environment and take appropriate measures for its control.

Rhizome Depth:

The severity of Japanese knotweed’s impact on structures and its ability to re-establish itself after treatment are closely tied to the depth and spread of its rhizomes (roots). To assess this accurately, surveyors must carefully evaluate soil disturbances and growth patterns to determine how deeply rooted the invasive plant is. By doing so, they can gain valuable insights into potential risk categories associated with infected areas, as well as potential growth patterns.

Site Map:

To accurately gauge the extent of Japanese knotweed infestation in a given area, surveyors will create detailed maps. These provide valuable information for ongoing monitoring and management efforts. With this data, experts can make informed decisions about how best to tackle problematic areas while minimising environmental impacts.

Treatment Options:

The knotweed specialist will provide recommendations for the most effective control and management methods based on their findings from the survey. These may include herbicide treatment, excavation, or another suitable treatment programme that is tailored to each situation and location.

Legal Obligations:

The survey will take into account any legal requirements or restrictions related to Japanese knotweed management, including adherence to the Wildlife and Countryside Act 1981. The results of the analysis will have significant implications for future control methods.

The Report

A qualified knotweed surveyor conducts the survey and produces a thorough report that highlights their findings, a risk assessment, and any treatment recommendations. The report is crucial for existing property owners, potential buyers, mortgage lenders, and insurers as it provides valuable information about the issues present on site. The report acts as an essential tool for making informed decisions regarding future actions being taken relating to the property and site.

A certified survey is the first step to understanding the growth of the knotweed and developing an effective management plan that will help you control the invasive plant and minimise its impact. Finding a knotweed specialist can help you make informed decisions about treatment options, which will also take measures to prevent further spread into neighbouring properties or natural areas. With careful planning and expertise from a specialist, managing Japanese knotweed doesn’t have to feel overwhelming.

If a Japanese knotweed survey confirms the presence of knotweed on your property, developing an effective management plan with a knotweed specialist is crucial. This involves taking steps that will control and mitigate its impact. The following are some actions you can expect to take:

Deciding on Treatment Method:

Based on a knotweed specialist’s analysis of your infestation, they will provide you with personalised treatment options. These can include herbicide application methods, excavating or burying affected areas, or a combination approach tailored to fit specific needs. 

Japanese Knotweed Survey

Management Strategy:

The effective Japanese knotweed treatment plan will include factors such as the timing of treatments, and follow-up actions required after each session, along with other considerations like proximity to structures or watercourses nearby, and local environmental regulations. The ultimate goal is always an efficient control and management process without causing any harm to the nature around it. 

Legal Obligations:

The knotweed management plan will ensure that legal obligations related to Japanese knotweed under the Wildlife and Countryside Act 1981 are all met so that legal action cannot be taken. It includes measures aimed at preventing the intentional spread of the weed into neighbouring properties or wild areas. This is crucial for maintaining ecological balance while protecting private property rights. With proper implementation by a knotweed specialist, we can keep our environment safe from invasive species like Japanese knotweed and prevent legal issues from occurring.

How Much Will It Cost?

Green Leaf Remediation offers a no-obligation site visit to identify if you have Japanese Knotweed at your property. From there, we would recommend a formal knotweed report is created, and we will advise you of the Japanese knotweed survey costs, which are dependent on your location and the size of your property. 

Following the creation of the knotweed report, a formal Japanese Knotweed Management Plan is created, which will include the recommended treatments, frequency, and costs.

The final amount may fluctuate depending on varying factors such as the infestation size, chosen treatment methods, or site complexity.

Once you have consented to the management plan and cost estimate, we will advise you of a date when we will return to your property to commence the treatments. These may involve multiple applications over several growing seasons for herbicide-based methods in particular. The goal is always to achieve successful treatment outcomes that meet your expectations and protect the environment and nature around you.

Continuous Monitoring:

The knotweed specialist will continue to conduct regular monitoring visits after the initial treatments to evaluate their effectiveness and detect any regrowth or new infestations as quickly as possible. This gives you peace of mind knowing that a professional who is familiar with the weed’s growth and behaviour patterns is guarding your property against potential future damage.


Throughout the process, you will receive updates and reports on how well treatments are progressing, as well as any necessary adjustments to management plans based on-site assessments and conditions. This ensures that you remain informed about what’s happening at every stage of treatment. With this information, any decision-making needed becomes easier and more effective than without.

Post-Treatment Obligations:

Following post-treatment instructions provided by specialists is crucial to preventing the further spread of Japanese knotweed. This includes adherence to site disturbance and plant disposal restrictions. Responsible waste management practices are also critical for controlling this invasive species effectively.

Green Leaf Remediation offers a ten-year insurance-backed guarantee that provides financial protection if regrowth occurs within a specified time frame after treatment has been completed. Opting for this type of guarantee gives you added peace of mind during an already unpredictable process. Our insurance-backed guarantees stay with the property, so if you move home, it gives your prospective buyers peace of mind that this is in place.

It is crucial to tackle Japanese knotweed infestations head-on and implement a comprehensive management plan that prevents further spread while minimising potential structural damage at the property in question. Engaging us as your qualified invasive species specialist ensures that control measures are applied accurately and effectively. With an effective management strategy in place along with consistent monitoring, you can successfully manage this problematic plant on your property over time.

If you are looking to sell your home or business premises, having a Japanese knotweed survey and management plan is crucial if you have or have ever had Japanese knotweed present. The property industry is becoming more and more aware of the issues and legalities of knotweed and could talk to you about the benefits of a formal Japanese knotweed survey. 

This will help inform potential buyers about any issues with this invasive plant species and the control and treatment that have been carried out. A formal Japanese knotweed management plan will appease some mortgage providers and mean they will still lend on a property where Japanese knotweed is or has been present.

If you are buying a new property, it makes sense to have an inspection done beforehand, especially if you are buying in a knotweed hotspot area. This means you will have peace of mind knowing there won’t be any surprises later down the line, which may also be a requirement of any mortgage applications you submit. If Japanese knotweed has not previously been discovered on the property, you may be able to obtain a Japanese knotweed indemnity policy. This type of insurance can protect the plant from future infestations and cover the costs of a specialised survey and treatment.

The presence of Japanese Knotweed, otherwise known as Fallopia japonica, and bamboo has become increasingly problematic over recent years due to their aggressive growth patterns, which make eradicating them challenging without professional intervention.

If you are concerned you may have Japanese Knotweed at your property or are buying in a hotspot area and you would like a site survey completed, please contact us at 01269 591651, or complete our contact form. We will be happy to answer any questions you have and arrange an appointment. We offer a no-obligation identification service and adhere to all professional standards.