Treating Japanese Knotweed

What is Japanese Knotweed?

Japanese Knotweed is an invasive plant/weed that was brought over to the UK by the Victorians. The British climate has the perfect conditions for knotweed to grow and does not have any natural enemy

Japanese Knotweed in the UK and therefore can become extremely thick and invasive.

Is Japanese Knotweed My Reponsibility?

The management of Japanese Knotweed is the responsibility of the owner/occupier of the site. Although there is no requirement by law to remove the knotweed, or control the invasive plant, it is recommended that action is taken immediately to help stem the spread of the weed. It is however an offense under the wildlife and countryside act of 1981 to purposely allow Japanese Knotweed to grow in the wild, outside your site or home. A Magistrate can impose an unlimited fine or even give a maximum prison sentence of 2 years! So it’s something to be aware of - you would not want to go to prison for “Knotweed”! The Knotweed is also treated as ‘controlled waste’ and should only be disposed of in a controlled environment.

How to treat Japanese Knotweed?

To control and remove Japanese Knotweed, there are a number of products on the market. Many professionals choose to use Roundup Pro Biactive, which is a professional product used by many grounds mantainance companies and local authorities. This is a chemical product and is only suitable for use by a qualified person. We also have a new product on the market; our Weedclear 450 is a great value high strength Glyphosate weedkiller. We also sell a knotweed package, which consists of 3 x Roundup Pro Biactive or 3 x SkilledBuild Weedclear. In the UK Knotweed can grow reaching 7m in all directions. The Japanese Knotweed itself is extremely brittle and if it is broken, the small pieces are actually capable of growing again. It is reported that knotweed can grow 4inches in a day from April to October. It should be noted that a repeated treatment should be undertaken annually to the affected area.

When should I treat Japanese Knotweed?

The best time to treat Japanese Knotweed with Glyphosate weedkillers is from flowering in August or September ensuring it is done before the plant starts to die back. It should also be noted that Japanese Knotweed is sensitive to frosts so applications should be made before the first frosts arrive. It can take up to 6 weeks for plants to show and parts of the plant should only be removed when there is no further sprouting.