Beautiful Plants For Your Interior
Japanese Knotweed and Japanese Knotweed removal is a hot topic for many gardeners in the UK.
Japanese knotweed (Reynoutria japonica/Fallopia japonica) are weeds that spread very rapidly. The Environment Agency has called Japanese knotweed, “indisputably the UK’s most aggressive, destructive and invasive plant.” This weed is so powerful that it can cause structural damage to homes or buildings.
In winter the plant dies back to ground level but in early summer, bamboo-like stems emerge from rhizomes deep below and shoot up to well over 7ft – (2.1m), suppressing all other plant growth nearby with its presence.
It can grow taller than any human can reach by hand and is very difficult to remove using chemical means of eradication. New legislation now covers control methods for this invasive species.
Philip von Siebold was a German physician, botanist and traveller, who was responsible for sparking an environmental disaster by bringing Japanese knotweed to the UK in 1850.
His introduction of this invasive weed (originally introduced to Britain as an ornamental garden plant) was met with widespread interest from society’s wealthy at the time, who were eager to cultivate it and share their knowledge of botany with others as a pastime.
As the years went by though, those same enthusiasts found that they would have never guessed at how much harm one small plant could do when left unchecked.
Japanese knotweed is a tall, strong, fast-growing, dense perennial that can grow up to 9.8ft (3m) high. It has slender deep penetrating creeping underground stems called rhizomes.
Japanese knotweed is an invasive, non-native species (in the UK) and it can be controlled by a few methods. Let’s look at the methods of control in this post and the government legislation now in place to cover its control.
Japanese knotweed can often be mistaken for other plants, like Fallopia baldschuanica (Russian vine) Leycesteria formosa (Himalayan honeysuckle) Houttuynia cordata (Fish Mint) and Persicaria microcephala (P. microcephala ‘Red Dragon’) so sometimes it can be difficult to identify correctly.
It should also not be confused with a less troublesome form of Japanese knotweed that is grown in gardens, namely Fallopia japonica var. compacta and its cultivars, which is the dwarf variety of the plant, that is much smaller in stature.
Those looking to identify invasive non-UK species of plants including Japanese Knotweed can see the GB Non-native Species Secretariat (NNSS) identification sheets for more information.
If you have identified that indeed you have Japanese Knotweed, removal is probably your next course of action. But beware, read the following paragraphs before you proceed further and decide on your next course of action.
For example; under the provisions made within Schedule 9 of the Wildlife and Countryside Act 1981, it is an offence to cause Japanese knotweed to grow in the wild and it’s illegal to cause it to spread by careless removal and dumping.
Therefore any such actions of Fly-tipping should be reported to The Environment Agency, free-phone number 0800 807060.
As we have discovered Japanese knotweed (Fallopia japonica) is an invasive species in the United Kingdom. In 2013, property sellers were required to state whether Japanese Knotweed (fallopia Japonica) could be found on their property.
This is communicated through a TA6 form or the old Property Information Questionnaire (PIQ) used for conveyancing.
This form will also include information about any other issues that may pose potential problems if they are not dealt with before selling your house.
Your solicitor or conveyancer should provide full legal advice about this.
As the seller, you are responsible for checking your property to find out about ‘Japanese Knotweed’ before you sell. The TA6 form asks you if it is ‘growing’ on your property, where it is growing, and what steps you have taken to provide a management plan from a professional company in order to eradicate the plant.
If you are buying property, the presence of Japanese Knotweed will be stated in the responses on the TA6 form.
If Japanese Knotweed is indeed present, this may often result in your mortgage lender requiring assurances that it will be eradicated before agreeing to the funds.
This process is often agreed upon between the seller and the buyer with an ‘approved’ management plan by a professional company for the controlled removal and eradication of the species. In addition, the lender will also possibly require a transferable guarantee to that effect.
This is usually sufficient for the lenders as it makes them feel better about providing funds, as Japanese Knotweed can cause major property damage if not dealt with properly and professionally.
If you’re a buyer or seller and want to avoid any potential problems down the line, it’s worth checking for Japanese knotweed.
Just be proactive, if disputes arise about the possibility of Japanese Knotweed on the property, failure to disclose their presence in advance may trigger ‘increased ‘costs’ later in the process – that’s not what anyone wants!
In addition, if someone claims that there was a misrepresentation, these issues could be costly and stressful long after a sale is complete. So make sure you take this pre-emptive step so all parties can enjoy a trouble-free sale.
Contact: The Royal Institute of Chartered Surveyors for survey information on Japanese Knotweed.
Search – ‘Japanese Knotweed’
In a recent amendment to the Anti-Social Behaviour, Crime and Policing Act 2014, invasive non-native plants like Japanese knotweed are included in the amendment. Here’s what this means for property owners:
If unchecked though, having Japanese Knotweed that could affect other people’s quality of life with persistent or continuing problems, then the legislation could be used to enforce its control and property owners may be prosecuted.
The RHS believes that by using good cultivation methods and introducing natural enemies, pests can be controlled without the use of chemicals (Cultural Control Methods).
However, if a serious threat does arise to our wider environment or important specimens, they recommend only minimal chemical control in targeted areas where necessary.
When it comes to Japanese knotweed, some of the recommended cultural controls don’t provide a long-term solution.
Japanese knotweed is a very tough weed to eradicate without professional help. The amount of time it takes depends on the size at to what extent the plant has grown.
It could take anything up to 3 or 4 seasons to remove them. Property owners who want Japanese Knotweed gone as quickly as possible should engage professionals with access to stronger, more regulated chemicals that can possibly reduce this time frame by half.
If undertaking yourself, always follow the safety instructions with regards to personal protection and in particular about how much product you need when using these powerful weedkillers, so you do not run into the risks of harming other plants, humans (children in particular) or pets.
It can be noted that Glyphosate is not active in the soil and there is, therefore, no risk that garden plants will absorb it through their roots.The inclusion of weedkiller products in this post does not indicate a recommendation or endorsement by Garden Junkie or any of its authors. It is simply an indication of products currently available to the home gardener.
Professional companies are equipped to deal with Japanese knotweed removal. They can report on risk for mortgage purposes, and provide the property owners with a treatment plan, as well as insurance-backed guarantees in cases where such guarantees are required by lenders.
The Royal Institution of Chartered Surveyors (RICS) has worked with the Property Care Association (PCA) to establish the PCA Invasive Weed Control Group (IWCG) trade body for Japanese knotweed specialists, which provides a register of vetted consultants and contractors.
For further information property owners can also contact:
Invasive Non-native Specialists Association (INNSA) maintains an updated membership list of contractors and consultants phone 0800 1300 485.
The British Association of Landscape Industries (BALI) has a good directory of members offering invasive weed control.
Trustmark Government Endorsed Standards also has a ‘Find a Tradesman’ scheme including invasive weed controllers.
Yes, Japanese Knotweed can grow back after removal if any small fragments of the plant are left behind. It is important to ensure that all plant material is completely removed and disposed of properly to prevent regrowth.
No, Japanese Knotweed cannot be burned or composted as it can spread easily through any fragments of the plant. It must be disposed of properly at a licensed waste facility.
The cost of Japanese Knotweed removal can vary drastically depending on the severity of the infestation and the location of the plant. On average, the cost can range from £2,500 to £5,000 for a small infestation and up to £20,000 or more for a larger infestation. It is recommended to obtain a quote from a reputable Japanese Knotweed removal specialist to get an accurate cost estimate.
As you can see, Japanese Knotweed is one of the most difficult invasive plant species to remove effectively. It has been declared an invasive species in the UK and carries hefty fines for those who are found guilty of not managing it properly on their property.
If you have any questions or concerns about your own situation with Japanese Knotweed, we encourage you to contact the professionals. They offer professional help that includes guarantee-based services so you never need to worry about whether you might be penalised for leaving behind some remnants of this plant during removal.
Contact them today if you want reliable information and expert guidance when it comes to providing efficient Japanese Knotweed removal once and for all!
Finally, you can always pop over to our FAQ page to find out more about Japanese Knotweed removal and a whole host of other answers to your gardening questions and queries.