How To Tell If You Have Japanese Knotweed

Something that all keen gardeners need to look out for is Japanese knotweed, a herbaceous perennial plant that somewhat resembles bamboo and has distinctive green shovel-shaped leaves. It grows incredibly quickly in all different types of soil and can soon take over your garden – and that of your neighbours – if you’re not careful.

Part of the problem with the plant is that it’s incredibly invasive and very difficult to get rid of, because you need to make sure you dig all of it up when trying to remove it. The plant grows from underground roots known as rhizomes and a new plant can grow if even the tiniest bit is left behind.

The fastest growth of Japanese knotweed takes place in spring, so keep an eye out for new reddish-purple shoots that look a little like asparagus spears. The leaves are usually rolled up and either red or dark green in colour. By late spring, canes can grow up to 10ft high. 

Come the summer time, leaves on the plant are green and shovel-shaped, sometimes up to 20cm in width and you should start to see small clusters of white flowers appearing in late summer and early autumn.

While it’s not illegal to have Japanese knotweed in your garden, it can make it difficult for you to take out a mortgage on a property that has the live plant growing onsite – and this can also make it difficult for you to sell your home in the future.

It can also cause issues with your neighbours if you don’t keep it under control and it invades their garden, leaving you open to costs incurred for removal or any damage caused.

Being prepared is your first line of defence, so make sure you know how to recognise the plant and treat anything as soon as you find it on your property.


For help with the patios in your Wirral home, get in touch with LW Landscapes today.