Customer Stuart Marshall recently contacted us about a suspicious plant that was growing in the back garden of his property in Aylesbury, Buckinghamshire. Unsure what it was, Stuart had attempted to dig the plant out when clearing the garden in preparation for selling the house, but when it kept growing back he became suspicious and contacted Environet for help.

We identified the plant as Bohemian knotweed, a rare hybrid of the highly invasive Japanese knotweed and its larger cousin Giant knotweed, which can be even more invasive and vigorous than both its parents. The plant will be excavated, which only takes a couple of days, with a root barrier installed to protect the property in the future.

Reports of Bohemian knotweed (Fallopia Bohemica) are on the rise, according to the Property Care Association. Unlike its parent plants, it has the ability to produce male plants and set seed, enabling it to spread more rapidly – and the fact that it’s not so easily recognised means it is often left to grow unchallenged.

As well as outcompeting native species, its vast root system has the potential to cause damage to property, including patios and driveways, which is seldom covered by buildings insurance, meaning the plant should be treated or removed as quickly as possible.

When selling a property, sellers are asked whether the property is affected by Japanese knotweed on The Law Society’s TA6 form. To the best of our knowledge it’s never been tested in Court whether this question also applies to hybrid varieties. To avoid the risk of future legal action our view is that sellers with hybrid varieties should respond to the TA6 as if it was Japanese knotweed, even though strictly speaking it is not.

How to identify Bohemian Knotweed

• It has green leaves which are either heart shaped or square ended. Both types can appear on the same plant.
• Leaves are larger than Japanese knotweed, but smaller than Giant knotweed, and have short hairs on the underside.
• Plants usually grow 2 – 3 metres high.
• It blooms in late summer, with small green-white or cream-white flowers that grow in plumed clusters.
• Cane-like stems are reddish-brown in colour. The plant dies back above ground in the autumn, but the canes usually remain standing.

If you’re suspicious of a plant in your back garden, we offer a free identification service. Just email a photo to [email protected] and we’ll let you know what you’re dealing with.