Japanese knotweed will not often spring to a landlord’s mind when ensuring that his property is kept properly maintained for his tenant. Unfortunately, Japanese knotweed is becoming an increasing issue in the UK and one that has the potential to leave a landlord’s property uninhabitable and/or ultimately unsellable if its encroaching presence is ignored. The Environment Agency has described it as one of the “most aggressive, destructive and invasive plants”. It spreads rapidly (up to a metre a month) and is very problematic and expensive to treat. It can cause substantial damage to buildings and infrastructure due to its ability to grow through concrete and tarmac and its roots are capable of growing down to a depth of four metres. Properties neighbouring railway lines are particularly infamous for Japanese knotweed. Landlords need to be increasingly vigilant seeing as they tend not to have permanent sight of the properties which they let. It is worth noting that – even if the tenant is responsible for the outdoor part of the property – it will be the landlord as landowner who will be held accountable should Japanese knotweed be present on his land.
Understandably, the main concern for landlords will be preventing any possible damage to their property. However there can also be other consequences which landlords need to know. Landlords have a duty of care to ensure that Japanese knotweed does not spread from their land. If a landlord causes Japanese knotweed to grow “in the wild” (as defined in the Wildlife and Countryside Act 1981), an unlimited fine and two years’ imprisonment can be imposed on the landlord. If the landlord allows the Japanese knotweed to spread to an adjoining property, the local authority can serve an “abatement notice” demanding it to be controlled. If the landlord breaches the abatement notice, this is an offence. Local authorities can also force landlords to treat their land if Japanese knotweed is found in their land or surrounding their land and there are potential criminal charges if not dealt with in a reasonable timeframe.
Case law has shown that the presence of Japanese knotweed is becoming a recurring issue. We have previously reported on the Williams v Network Rail Infrastructure Limited  EWCA Civ 1514 case which saw private individuals claiming against Network Rail. Network Rail had allowed Japanese knotweed to cultivate on its land which had then encroached onto the private individuals’ land (for more information please see ‘Japanese knotweed: The nightmare neighbour’). The claim in private nuisance resulted in the court of appeal ruling that a landowner could claim damages if Japanese knotweed is found to have encroached on their property. Recently, Bristol City Council used the Anti-Social Behaviour, Crime and Policing Act 2014 (“Act”) to prosecute the property owner MB Estate Ltd (“MB”) for allowing the spread of Japanese knotweed onto seven neighbouring properties. MB were fined £18,000 plus costs and had to remedy the issue within 28 days of the order. This is a thought-provoking development as it is one of the first prosecutions relating to Japanese knotweed which has used this Act and suggests that there will be more to follow.
In terms of practical guidance, it is clear that landlords must regularly inspect their properties for the existence of Japanese knotweed and must take swift action if it has been identified. If Japanese knotweed is to be removed, there is guidance in the “Environment Agency Knotweed Code of Practice” which can assist and a professional removal service should be hired. It is also possible for landlords to include certain provisions in their leases to try and protect themselves from this risk, such as: