What to do if a neighbour has Japanese Knotweed? Find out more about the law on Japanese Knotweed and if Japanese Knotweed spread from one garden to another?

Having a Japanese Knotweed infestation in your garden is an annoyance for many homeowners, with this invasive plant causing structural damage in residential properties across England. What should you do when your neighbour has Japanese Knotweed in their garden? Keep reading this article if a neighbouring property has this invasive plant. 

The law on Japanese Knotweed

When it comes to Japanese Knotweed removal, there are legal obligations homeowners must follow across the United Kingdom. England, Wales and Northern Ireland differ from Scotland. Property owners should consult an invasive weed specialist and ensure they follow the Wildlife and Countryside Act 1981 when removing Knotweed. 

f your neighbour has Japanese Knotweed growing in and around their property, they have no legal obligation to remove it. However, when the plant moves from the neighbouring land to yours, this is a private nuisance, and you can raise court action.

As Japanese Knotweed spreads, it can cause more damage to properties and gardens, which is why an infestation next door must be treated as soon as possible. 

Japanese Knotweed Growing In Neighbour's Garden

A knotweed infestation in your neighbour's garden leads to many arguments about removal, and you can make a nuisance claim when it begins affecting the health of your garden or property. There are many laws relating to what action you can take to treat Japanese Knotweed (and plants as a whole) on a neighbouring property.

While the plant has a negative effect on surrounding wildlife, you are not permitted to intervene when it does not affect you. The first thing in Japanese Knotweed control is not legal action or a dispute. Instead, you should identify the plant correctly. Perhaps your neighbour has not realised it is growing on the adjacent property to your own, or perhaps they have mistaken it for another plant, not realising the serious damage it can cause. 

• Knotweed can cause significant structural damage to properties, breaching weak spots in foundations.
• Insurance companies don't cover damages caused by invasive weeds.
• Mortgage lenders are hesitant to lend on properties where Knotweed is found.
• When left, Knotweed requires property surveyors and professionals to remove it, costing up to £72 per tonne in tax for removal costs.
• The Environment Agency outlines roots can extend up to 7 metres from the visible plant, going as deep as 3 metres. 

While it is your neighbour's responsibility to remove it while it remains in their garden, you can alert them to the issue and catch it in the bud before it spreads to your own property. If it has, this can constitute legal advice, as tackling the root barrier will take precision so as not to spread it further. 

Can Japanese Knotweed in a neighbour's garden affect a house's value?

Knotweed moving from one property to another can cause a loss in profits, with the damage caused affecting the property for several years. As Knotweed spreads from being disturbed and through the roots underground, your site can become infested before you realise it. If the Knotweed remains in the neighbour's garden, the caused damage is minimised.

Property surveyors may estimate how much money you will lose, but this depends on how close the Knotweed encroaches on your property. The closer it gets, the more detrimental effects you will experience. Most surveys state that if Knotweed is found within 7 metres of your property, you will likely lose value. This is why it's crucial you eradicate the problem as early as possible, but treatments require precision, as you are likely to spread it further when tackling it yourself. This is illegal, so always contact a professional for the remedy. 

Can Japanese Knotweed spread from one garden to another?

Japanese Knotweed does not spread like other plants, as only the female variation of Knotweed was introduced to the UK. However, they still present a threat. Knotweed can spread from one property to another, especially in the summer months when you are unaware of its presence. Underground, the Knotweed has an extensive rhizome root system which is able to spread rapidly.

This is the same from your neighbour's property to your own, as a fence will not keep these plants out. It's worth noting there are legal implications to attempting to remove the Knotweed yourself when it spreads. You are liable to be fined or imprisoned if you deal with this weed incorrectly, so the first step is always to alert someone authorised to deal with the issue. Knotweed must be burnt on-site or removed carefully and burnt elsewhere, away from the soil.