Beware Of Japanese Knotweed Near Your Holiday Home

Japanese knotweed (Fallopia japonica) near your holiday home can present a real problem. This plant is highly invasive and can grow at a rate of 10 centimetres per day. It can quickly take advantage of weaknesses in building materials, paths and roads to become a serious threat to the integrity of your holiday home. This is a particular issue if you want to resell or are looking to buy. It is also suffocating to the growth of other plants.

The ability of Japanese knotweed to grow extremely rapidly from very small sections of rhizome (underground creeping roots) and the depth at which the rhizome grows (up to 2 metres) makes it very difficult to eradicate. This is one of the reasons that it is highly recommended to get a professional company in to control any Japanese Knotweed you find on your property.

Legal requirements

It is now (since 2013) a legal requirement to declare any Japanese knotweed that is on a property. Measures to undertake its removal are normally required by mortgage companies before any funds are released. Whether you are buying or selling, it is a good idea to check that the property is free of Japanese Knotweed or that a management plan is in place to eradicate it at the earliest possible time.

While it is not illegal to have Japanese knotweed on your property, allowing its unmanaged growth and spread to other properties can result in liability for damages and the cost of removal and the possibly of prosecution. It is your responsibility to avoid a “detrimental effect of a persistent or continuing nature on the quality of life of those in the locality”.

It is strictly illegal to cause it to grow in the wild, so disposal of Japanese knotweed is strictly controlled.

If you have some Japanese knotweed growing at your holiday home, it is very important to have it managed, controlled and eradicated. Even though it presents no direct health risk, to prevent it spreading, if you are letting out your holiday home, alert your guests to stay clear of it. Fence it off in some way that makes it inaccessible to them or their pets.

Identifying Japanese knotweed

It is possible to confuse Japanese knotweed with Russian vine, Himalayan honeysuckle, heart-leaved houttuynia and knotweed ‘Red Dragon’. So, identifying Japanese knotweed can prove to be tricky. However, there are many organisations and websites which can provide help if you send them photographs of the suspected plant. The Royal Horticultural Society is a particularly useful place to start enquiries about Japanese Knotweed and for members, will help identify it for you on receipt of photographs. Also, see the GB Non-native species Secretariat (NNSS) identification sheets for invasive non-native species including Japanese knotweed.

Do NOT send samples.

It is useful to familiarise yourself with the various stages of its life cycle and how Japanese knotweed presents in each season.

  • Spring:

Reddish-purple fleshy shoots emerge from crimson-pink buds at ground level.

  • Summer:

Dense clumps of bamboo-like canes with purple flecks, which can grow to 2.1m/7’.

Leaves are shovel or heart shaped and grow in a zig-zag pattern along the stems.

  • Autumn:

Creamy white flower tassels are produced from late summer into early Autumn. Leaves yellow and redden and fall and the stems begin to dry.

  • Winter:

The stems die back to ground level but the dry canes remain.

Eradicating Japanese knotweed

As we have already noted, the depth of the rhizome or root system and the ability of Japanese knotweed to grow from a very small piece of rhizome make its eradication a particularly difficult task. It usually takes about three or four seasons with weed-killer to kill it off. Holiday home owners could perhaps consider controlling the weed themselves if it is only occurring in a small isolated clump. However, Japanese knotweed is known as ‘controlled waste’ and is classified under the Environmental Protection Act 1990 so that it can only be disposed of in licensed landfill sites.

The only other way of safely disposing of Japanese knotweed is to allow it to thoroughly dry first and then to burn it.

Seek professional help

If you want to be rid of it and have a guarantee of this, then turn to a professional. Professional contractors will have access to more powerful weed-killers than those available to gardeners on the commercial market. This can halve the time it takes to kill off the plant.

A professional contractor will hold all the licenses to carry and dispose of controlled waste. They will also be able to offer insurance-backed guarantees and mortgage reports if you are selling your holiday home.

On NO ACCOUNT place Japanese knotweed in ordinary waste or garden waste disposal. 

To find a reliable contractor you can turn to a number of bodies. You will find a register of vetted contractors at the PCA Invasive Weed Control Group (IWCG) and also with the Invasive Non-native Specialists Association (INNSA) or on the ‘Find A Tradesman’ scheme run by Trustmark Government Endorsed Standards organisation.

The key to controlling Japanese knotweed is to identify fast and act early. Bring in a professional contractor at the first possible opportunity.

This is a marketing article from My Holiday Home Insurance, a specialist provider of insurance for all types of holiday homes. Our team of experienced advisers are always happy to help, so for more information call our Northampton office on freephone 0800 988 0890.