How To Get Rid of Japanese Knotweed – Griggs Homes

How To Get Rid of Japanese Knotweed

Japanese knotweed is a potent weed known for its ability to damage structures. It is also extremely difficult to treat and eradicate.


What is Japanese Knotweed?

Japanese knotweed is a perennial with tall, dense and fast-growing stems. The weeds form in dense clumps. Initially, the plant was brought over to the United Kingdom as an ornamental garden plant but has quickly become a problem due to its fast-growing nature and difficulty to eradicate.


Why is Knotweed So Bad?

The main problem with Japanese knotweed is its tenaciousness and ability to grow through concrete or brick. For this reason, it has the potential to do serious structural damage to buildings and roads.

Japanese knotweed always grows in dense clusters making it difficult to find the root. It is also notoriously difficult to get rid of and remove.


Does Japanese Knotweed Ever Go Away?

Japanese knotweed currently has no known cure. According to the world’s biggest ever study, carried out by Swansea University, 19 different methods over the course of 3 years failed to successfully get rid of the knotweed.


Does Japanese Knotweed Have Any Benefits?

Despite its problems, Japanese knotweed has its uses, especially in a medical capacity. It is a known cure for bronchitis, coughs, sore throats and gum disease. Additionally, it is used for skin disorders, lung diseases and fluid retention. In some areas, Japanese knotweed has been used to stop bleeding and reduce illness-related sweating.


What Kills Japanese Knotweed?

Japanese knotweed is known for how difficult it is to eradicate. However, there are some substances which are thought to be good at killing, or at least controlling, the weed.

The chemical glyphosate is thought to be one of the most effective substances for controlling Japanese knotweed so any glyphosate-based herbicides are recommended.


Home Remedies to Kill Japanese Knotweed

Vinegar, due to its acidity, can be used to treat Japanese knotweed by killing the foliage and stalks.

Another strategy is applying salt to the plant. This is a very long process as it involves the plant dehydrating over time and eventually dying. For a weed as potent as the Japanese knotweed, this method is not very effective.

You can also inject certain herbicides and fungi into the knotweed stems which can kill the target plant without threatening the lives of any neighbouring plants.

Japanese knotweed

Japanese Knotweed is hard to remove and it can impact the structure of the property. But it can be removed with the use of vinegar, salt or the help of a professional

When is the Best Time to Treat Japanese Knotweed?

If you are treating Japanese knotweed by spraying it with herbicides, the best time to do this is during late summer or early autumn. This is because this is when the plant is flowering so the herbicides can access the rhizome where the plants build their food reserves.


Does Cutting Japanese Knotweed Kill It?

Cutting the knotweed can help to control and manage the weed but it does not kill it. This is because it only removes the part of the plant that is above ground.

Saying that, depending on the severity of the problem, regular mowing can eventually work to kill the plant by drawing down the plant’s reserves over time.

The best known combination for treating Japanese knotweed growth yourself is through a combination of cutting and applying herbicides.


Can You Sell A House With Japanese Knotweed?

If your property has Japanese knotweed, you should make it known to the potential buyers. You may also need to take additional measures to ensure confidence in the buyers. Japanese knotweed has the potential to affect things such as securing a mortgage from the bank so it is definitely worth telling any prospective buyers.


Should You Buy a House with Japanese Knotweed?

Japanese knotweed can devalue a house between anything from 5% to 15% and, at its most severe, can leave a property completely valueless. Before buying a property with Japanese knotweed, you need to consider how severe the infestation is. See also, ways to increase the value of your home.


Can I Rent A House with Japanese Knotweed?

If you are renting a property and you discover that there is Japanese knotweed, you should get in touch with your landlord as soon as possible due to the impact it can have on the structure.

When renting, it may be that the maintenance of the garden is the tenant’s responsibility; however, you should still alert your landlord as they will probably need to look into treatment or removal of the weed.


What Do I Do If My Neighbour has Japanese Knotweed?

If your neighbour has Japanese knotweed, you need to make it known to them as soon as possible. It is their responsibility to treat the problem and try and get it removed - however, they are not under any legal obligation to remove the Japanese knotweed from their property.

Should the Japanese knotweed begin to encroach on your property, you may be able to make a claim against your neighbours as the problem can be considered a private nuisance.