A: If you suspect that the plant is growing on your property, you are legally responsible to declare this fact and stop it from spreading. We strongly recommend that you contact a professional knotweed control company to eradicate the problem. To identify the plant, look for fleshy red shoots, large heart-shaped leaves that are growing in a zig-zag pattern along the hollow stems, clusters of cream flowers in the summer and upright-standing stems in the winter.
Get an Expert Japanese Knotweed Eradication Plan & Removal
Identifying the knotweed invasion on time & devising an effective eradication plan!
- Reputable knotweed control company
- Service guarantees of 5 to 10 years
- On-site inspections, free of charge
- Nationwide service coverage (excl. Scotland)
How Does the Japanese Knotweed Service Usually Go?
Fantastic Gardeners has partnered with a certified contractor and accredited invasive plants removal company, which has been deemed the best knotweed eradication service provider in the UK for 2017. Our partner works with NTPC-qualified and fully experienced technicians who are certified to employ professional-grade products and effective methods that have been approved by the Environmental Agency and SEPA.
Here’s what the knotweed identification process involves and what you can expect from the service:
- Request an on-site inspection - Book online or call us and we will arrange your free on-site survey with a knotweed removal expert.
- Meet the professional - The gardener will inspect carefully your property and confirm whether the invasive plant is present and to what extent it has spread.
- Confirm your decision - If you decide to work further with us, the expert will send you a survey report, a 5-to-15-years knotweed eradication plan, and a quote. The fee for the report will be subsequently deducted from your price quotation, should you proceed with the plan and treatment.
- The knotweed removal plan is applied - You’ll be invoiced and the first treatment session will take place on a day of your convenience.
Japanese Knotweed Removal Methods We Use
Depending on the scale of the issue and other factors, a range of knotweed control and removal methods can be applied:
- Herbicidal treatment - The method is very much used on large sites that suffer from an extensive knotweed invasion. The treatment may take up to 24 months so that complete eradication is achieved.
- Stem injection - A highly effective targeted treatment, suitable for application in environmentally sensitive areas.
- Excavation - The technique is used on active building sites, where once identified, the plants are excavated and treated on-site in a designated area, relocated on-site and buried in a sealed plastic membrane or they are disposed of in a licensed landfill.
- Root barriers - The knotweed root barrier installation is a preventative measure only, designed to stop the plant from spreading into a neighbouring property, for instance.
- Sifting and screening - The method is designed to reduce the cost of removing and burying a large quantity of contaminated soil prior to building work, for example. The top layer of the soil is sifted and screened for the presence of knotweed. The process takes no more than a couple of days.
Japanese knotweed removal specialists
Ignat Asenov
Number of bookings: 5126
With Fantastic Services for: 3 months
Specialities:
Plamen Karaminchev
Number of bookings: 3314
With Fantastic Services for: 7 years
Specialities:
Svetoslav Peshev
Number of bookings: 680
With Fantastic Services for: 5 years
Specialities:
Frequently asked questions
Q: How can I tell if I’ve got Japanese Knotweed in my garden and what should I do if I find any?
Q: How worried should I be about Japanese knotweed?
A: Japanese knotweed is one of the most invasive and damaging plants in the UK. If left untreated, it can weaken building foundations, block drains, damage walls, and significantly reduce property value. Mortgage lenders may also refuse loans if knotweed is present. While it’s not dangerous to people or animals directly, the legal and financial implications make it a serious issue. If you suspect its presence, book a free on-site inspection with our certified specialists to assess the risk and begin professional eradication before the problem worsens.
Q: Is the Japanese Knotweed toxic and when is the best time to apply the treatment?
A: Knotweed is not harmful to people but you risk spreading it if you touch it. If the treatment method involves the use of herbicides, they are usually applied in the summer.
Q: How fast does the plant grow?
A: As the UK’s most destructive and invasive plant, you need to know that the plant can reach up to 4 metres in 10 weeks (growing 10-20 cm per day). The roots of the plant can grow up to 3 metres deep and up to 7 metres horizontally.
Q: How far down do Japanese knotweed roots go?
A: Japanese knotweed roots,technically known as rhizomes can grow as deep as 3 metres (10 feet) into the ground and spread up to 7 metres (23 feet) horizontally. This extensive root system makes the plant extremely invasive and difficult to eradicate without professional help.
Q: Can you spread Japanese knotweed by walking on it?
A: Yes, Japanese knotweed can easily spread through human activity. Walking on the plant or disturbing its rhizomes (roots) can break off small fragments, which may then establish new growth if moved to another area. This is why it's illegal to allow it to spread into the wild and why DIY attempts can often make the problem worse. Our professional eradication services follow strict environmental protocols to prevent further spread during removal.
Q: Can the plant cause damags to buildings?
A: Absolutely, hence the strict legislation, regarding its control. “In search” of water, weak spots in the building and cracks, the roots can weaken the foundations of your property, cause subsidence through disturbing the soil, as well as block drains.
Q: Can Japanese knotweed grow through concrete?
A: Japanese knotweed cannot grow through solid concrete, but it can exploit existing cracks, weaknesses, or joints in concrete, tarmac, and masonry. Its powerful root system can extend several metres in depth and spread horizontally, making it capable of widening structural faults over time. This is why professional identification and treatment are essential, our certified knotweed specialists can assess the extent of the infestation and provide a guaranteed plan to stop it from causing costly damage.
Q: What is the 7 metre rule for Japanese knotweed?
A: The "7 metre rule" refers to guidance used by surveyors and lenders, stating that Japanese knotweed can spread underground up to 7 metres from the visible part of the plant. This means if knotweed is found within 7 metres of a building, wall, or boundary, it could pose a risk to structures and must be assessed carefully. While the rule is no longer part of official RICS guidance, many mortgage lenders still use it as a benchmark. Our certified specialists can provide a thorough survey and management plan to meet lender requirements.
Q: Does Japanese knotweed devalue your house?
A: Yes, Japanese knotweed can significantly devalue a property by as much as 5–15% or more, depending on the extent of the infestation and whether a professional removal plan is in place. Its invasive nature and potential to cause structural damage make mortgage lenders cautious, often requiring evidence of a certified treatment plan with a long-term guarantee. Our service includes an on-site inspection and eradication plan, which can help reassure buyers and lenders, restoring property value and marketability.
Q: Can I get a mortgage or sell my house if there is knotweed on the property?
A: Mortgage lenders may require a survey report prior to making a decision to lend you the money. The bank may reject your application or request from you pay for a professional eradication treatment before you are presented with a mortgage offer. Regarding selling your property, you are legally liable to let the buyer know about the problem. You’ll be committing an offence if you hide the presence of knotweed in your garden.
Q: Does home insurance cover Japanese knotweed?
A: Most standard home insurance policies in the UK do not cover damage caused by Japanese knotweed. However, some insurers may assist with the cost of treatment if the knotweed causes structural damage that falls under your policy’s terms. It's best to check the specifics of your insurance cover. If you discover knotweed, it’s essential to act quickly and seek professional help, as the presence of the plant can affect your property’s value and mortgage eligibility.
Q: Is it illegal to have Japanese knotweed in your garden?
A: It is not illegal to have Japanese knotweed on your property in the UK. However, it is illegal to allow it to spread into the wild or onto neighbouring land, as this is considered a criminal offence under the Wildlife and Countryside Act 1981. If you discover Japanese knotweed in your garden, you are legally responsible for preventing its spread. Professional removal services, like those we offer can help you stay compliant and avoid serious legal and financial consequences.
Q: Can I remove Japanese knotweed myself?
A: While it is legally possible to attempt removal of Japanese knotweed yourself, it is not recommended. The plant spreads aggressively through its root system (rhizomes), and improper handling, such as cutting, composting, or disposing of it in general waste can lead to further spread and even legal consequences. Under UK law, knotweed is considered controlled waste and must be disposed of at a licensed facility. For safe, effective, and guaranteed results, it’s best to hire certified professionals who follow Environment Agency guidelines and can provide a long-term eradication plan with a warranty.
Q: What happens if you cut down Japanese knotweed?
A: Cutting down Japanese knotweed without proper follow-up can actually worsen the problem. While trimming may reduce the visible growth temporarily, the plant’s extensive underground rhizome system remains active and can quickly regenerate. Improper disposal of cuttings is also illegal, as the plant is classified as controlled waste under UK law. To ensure effective and legal eradication, always consult with licensed knotweed removal specialists.
Q: How can I dispose of knotweed? Can I burn it, for instance?
A: Under the Environmental Protection Act 1990, the aggressively growing plant is considered a controlled waste. Only licensed waste removal providers can take it away to a specialised landfill. If you decide to burn the plant, this must be done on your property after the plant has been cut down and dried on a plastic sheet, first. Dumping knotweed anywhere in the countryside may land you with a hefty fine.
Q: Can you put Japanese knotweed in the bin?
A: No, you must not put Japanese knotweed in your household or garden waste bin. It is classified as controlled waste under the Environmental Protection Act 1990, meaning it can only be disposed of by licensed waste carriers at authorised landfill sites. Improper disposal, such as placing it in your bin or dumping it elsewhere can lead to severe legal penalties. Always use a professional knotweed removal service to ensure safe and legal handling.
Q: Can Japanese knotweed be permanently removed?
A: Yes, but it requires a professional approach and patience. Japanese knotweed is notoriously persistent due to its deep rhizome system. Permanent removal often involves a combination of targeted herbicide treatments, stem injections, or excavation over a period of time. At Fantastic Gardeners, we offer eradication plans with service guarantees of up to 10 years, ensuring that the plant is effectively controlled and monitored to prevent regrowth.
Q: What is the best knotweed removal method?
A: The best method for removing Japanese knotweed depends on the extent of the infestation and the property type. For large or persistent infestations, a professional herbicidal treatment plan applied over multiple seasons is often most effective. In cases requiring immediate removal, such as during construction, excavation and licensed disposal may be necessary. Stem injection is another precise method used in sensitive environments. Our certified experts will assess your situation during a free on-site inspection and recommend the most effective treatment plan, backed by a 5–10 year guarantee.
Q: How often should you spray Japanese knotweed?
A: Japanese knotweed typically requires herbicidal treatment once or twice per growing season, depending on the severity of the infestation and the chosen product. Treatments are most effective when applied in late summer to early autumn, when the plant is actively transporting nutrients to its roots. Complete eradication often requires repeated applications over 2 to 3 years, which is why it’s best handled by professionals who can monitor progress and adjust the treatment plan as needed.
Q: How much is the cost of professional knotweed removal?
A: A precise quote can be given only after an on-site survey has taken place. The cost will depend on the severity of the plant invasion and the methods used to eradicate the issue. The survey report costs £360 (incl. VAT) and the fee is deductible from the quotation.
Q: Does the service come with a guarantee?
A: Yes. Based on the type of plan and removal treatment you select, you will receive from 5 to 10 years of guarantee.
Q: Does the knotweed control contractor deal with other invasive plants?
A: Yes. You can get help with identifying and eradicating Himalayan Balsam, Horsetail, Giant Hogweed, Ragwort, Buddleja Davidii and more.
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