How to control Japanese knotweed

Japanese knotweed was first brought to the UK as an attractive ornamental plant in the 1840s, but fell out of favour, and since the early 1900s came to be seen as somewhat of as a scourge. To this day, the invasive plant has caused difficulties for houseowners, landowners and developers. Knowing how to control Japanese knotweed effectively can remove much of the stress from the situation and help safeguard the value of your property or land you own. 

For domestic property owners, in-situ Japanese knotweed control rather than mechanical removal is a common treatment option, especially if they are intending to stay at the property for many years. As there is no requirement to remove Japanese knotweed, merely an obligation to prevent it spreading to nearby properties, a programme of control to keep it manageable may be an option.  

Alternatively, a solution of complete removal may be considered the best option, especially if you want complete piece of mind that the problem has been eradicated for good. 

How can Japanese knotweed be controlled?

There are several options for effective Japanese knotweed control. There are different methods, such as chemical, onsite burial and offsite removal, that can be used to control the invasive plant. Much depends on the severity of the presence at your property, as well as environmental factors (such as proximity of nearby waterways) as well as your personal circumstances.  

It is important if you have Japanese knotweed on your property, that you start treatment as soon as possible to prevent further spread and potential long-term structural damage. 

The most commonly used method of Japanese knotweed control is via chemical control with herbicides, usually glyphosate-based products. This method is highly effective and the most cost-effective, but complete eradication does take around 3 to 5 years to complete, especially when the infestation is well established. 

Treatment will usually involve the chemicals be sprayed on the foliage of the weed. However, it can also be injected into the stem, which can be an especially useful method when being used in ecologically sensitive areas, or when you don’t wish to contaminate neighbouring plants. 

Repeat spraying to the foliage (or stem injection) will usually be carried out during the growing season. This is best performed in later summer/early autumn, at a time when the plant is in full leaf and flowering. By spraying onto the leaves at this point means that the plant, when it would usually be looking to build food reserves, will instead carry the herbicides into the root system and start to destroy the rhizomes, eventually preventing regrowth of the knotweed.  

In cases where more immediate removal is required, often on commercial or development sites, then Japanese knotweed excavation may be the preferred option. For most domestic premises though, chemical control will usually prove the most cost-effective option. 

Can Japanese knotweed come back?

If you fail to have effective Japanese knotweed control in the first place then it is possible and quite likely that it will return. This is why we don’t recommend DIY solutions at Japanese knotweed removal. 

Every last trace of the root, down to the last thumb-nail sized piece needs to be removed to ensure that it can’t re-grow. 

Some people may make the mistake when they first find Japanese knotweed on their land of cutting it down, without proper consideration of what is going on underground. By cutting down the plant, may in fact, give the plant a chance to disperse on your land, as well as potentially spreading it to neighbouring properties, especially if the cuttings have not been properly disposed of. 

Owners of land where Japanese knotweed is present have a legal obligation to ensure that any invasive plants that are present do not spread to neighbouring properties. That is why it is highly advisable to employ the services of a professional Japanese knotweed removal company to tackle your problem. 

By building a greater understanding of Japanese knotweed control will go a long way to helping you make the best decision for your property. Knowing how to control Japanese knotweed will give you an understanding of how the support of a professional team will take the hassle and worry from your knotweed problem. 

By hiring a company like JKQ with expertise in Japanese knotweed removal and control, who will carry out their work with a guarantee, you can be confident that your knotweed problem is removed for good.