Posted by Admin - 09/11/2015


Japanese Knotweed was first introduced to the UK in the mid nineteenth century. It was first planted at Kew gardens and recommended by the Royal Horticultural Society to stabilise river and railway embankments.

Japanese Knotweed is an extremely aggressive and rapidly growing perennial capable of growing a foot a week and spreading up to 7 meters in all directions per season.

With no natural enemy its invasive nature causes problems for native wildlife as well as the built environment and its related infrastructure.  If left unchecked, Japanese Knotweed will continue to spread, producing dense clumps of growth up to 3 metres in height.

It does not spread by seed but produces a dense rhizome network beneath the ground from which the smallest fragment will re-grow.

It is generally spread by human activity such as fly tipping or cross contamination, and small pieces of the plant i.e. a leaf or shoots will easily re-grow in the right conditions.


The Law.  The Wildlife and Countryside Act (WCA) 1981 states that it is an offence to plant or otherwise cause Knotweed to grow in the wild.

The Environmental Protection Act (EPA) 1990 Duty of Care Regulations 1991 has specific legislation relating to Japanese Knotweed.

Third Party Litigation – where you can be sued for costs if you allow Japanese Knotweed to spread from your property onto that of an adjacent land owner.

Failure to dispose of waste material containing Japanese Knotweed may lead to prosecution under section 34 of the Environmental Protection Act 1990.

As of November 2014 ‘ASBO’s’ or Community Protection notices can now be issued to land owners with Japanese knotweed.

Home owner responsibilities.  As a home owner your primary responsibility is to ensure that if you have knotweed on your land it should not be allowed to spread onto an adjacent property.  It is not currently illegal to have Japanese Knotweed on your property and provided you do not allow it to spread onto a neighbours land then nobody can make you do anything about it.

What should I do if it’s growing in to my property from adjacent land?  The law will be on your side if you enter in to dispute with a neighbour who has allowed Japanese Knotweed to grow on to your land, however, our best advice would always be to keep friendly! Try and discuss the problem with your neighbour – advise them of the problems and discuss how best to deal with the problem (at their expense!). It is always easier to come to an agreed compromise than to go shouting the law at people. It can also occasionally backfire as well – should the origin of the infestation prove to have been on your property not theirs!…

How do I get rid of it?  Japanese Knotweed will not compost and does not respond well to cutting or in-situ burning which often actually stimulate increased growth.  Cutting and pulling the plant from the ground is not advisable as this can also stimulate new growth.

1. Fence off all areas of Japanese Knotweed at least 7 meters away from surface growth.

2. Have a foot washing facility to clean shoes when leaving contaminated area.

3. Carry out an initial spray with a Glyphosate based weed killer such as ‘Roundup’.

4. Leave for chemical suppliers recommended period to allow chemical to be absorbed by plant.

5. Remove all surface growth to a height of 150mm above the crown of the plant.

6. Leave to dry in an area not subject to traffic and in piles that will not be disturbed.

7. Incinerate all removed surface growth.

8. Check Environment Agency web site for document entitled Management of Japanese Knotweed and look at pictures of rhizome to enable identification.

9. By hand, excavate the surface crown and all visible rhizome – this may extend as deep as two meters underground and 7 meters beyond surface growth.

10. Dry all rhizome and crown material by placing on a sheet of polythene and keeping away from moisture.

11. Once rhizome and crown have dried out incinerate within your contaminated area.

12. Check and monitor for re-growth over the next five years and repeat as necessary.