Japanese knotweed or Donkey Rhubarb to those in the horticulture world is an invasive, non-native plant that can cause physical damage to buildings and land, which can affect the value of the property, and can be expensive and difficult to eradicate or treat.
Homeowners are being warned to prepare for a ‘Super Spring’ of Japanese knotweed growth as warm temperatures sweep across the UK this time of the year, with the invasive plant species risking damage to homes and devaluing house prices by as much as 10%.
The Government has issued guidance on invasive plants such as Japanese knotweed, and it states that not only have you got to prevent invasive non-native plants spreading on your land, you also must prevent harmful weeds on your land spreading onto a neighbour’s property. You can be fined up to £5,000 or sent to prison for up to 2 years if you allow contaminated soil or plant material from any waste you transfer to spread into the wild.
The common features of Japanese Knotweed to look out for include:
- Dense thickets of green, purple-speckled, bamboo-like stems up to three metres tall
- Heart or shield-shaped leaves
- Alternate leafing pattern along stems
- Completely hollow stems that can be snapped easily
- Tiny creamy white flowers August to October.
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For more information on how to identify these and what to do if you do find it, read the Royal Horticultural Society or Government guidance.
Why do I need to know about this when Buying or Selling a Property?
When you are buying a property, you will receive a Property Information Form filled in by the seller. There is a standard protocol question on whether the property has been affected by Japanese knotweed and if so, whether there is a management plan in place. The form does not ask about other invasive plants.
However, if the seller states there is not Japanese knotweed and there is, this may not necessarily be relied upon.
Building insurance may not cover for Japanese knotweed if it is found. Usually policies state the owner has to do everything they can to prevent damage to a home and ignoring the presence of a plant may mean that any claim is denied.
Some mortgage lenders have made changes to their requirements for Japanese knotweed. For example, HSBC need to be informed if you become aware that there is, may be or has previously been Japanese Knotweed identified on or near the property.
Landowners have a measured duty of care to ensure that Japanese Knotweed does not spread from their land, following the Court of Appeal decision in Williams v Network Rail Infrastructure Limited. Even in cases where no actual physical damage has been caused, the court decision opens up claims by neighbours for loss of amenity value due to the hazard created by the mere presence of the plant’s rhizomes under their property.
The judgment makes it clear that landowners must take reasonable steps to prevent or minimise the spread of Japanese Knotweed across the boundary. Whether a defendant has taken ‘reasonable’ measures is determined on a case by case basis, but guidance can be found in the long line of nuisance cases where the interaction between neighbouring landowners is assessed on a ‘give and take’ basis.
Our experience from numerous environmental nuisance cases is that there is no ‘one size fits all’ test for reasonableness in nuisance, and landowners will need to be careful that their actions (or inactions) fall the right side of the line.
If you are concerned about Japanese knotweed on the property you are purchasing or a neighbouring property, then talk to your solicitor. There are a range of options available, including indemnity insurance, or having a specialist knotweed survey and assessment. If any work has been done to Japanese knotweed to eradicate it, it is worth considering using a specialist company that will provide a guarantee.
For more information, please call Gwyn James Solicitors on 01600 775950
