Understanding Knotweed Identification
When you have identified a garden pest, it’s important to understand what your dealing with. Japanese Knotweed is particularly adequate at disguising itself, and can have a different appearance depending on the time of year.
Red or purple shoots appear and grow into canes which sprout leaves that later unfurl and turn green.
Japanese knotweed is fully grown in the summer, the canes are matured and hollow and hold a distinctive purple speckle. They can grow up to three metres high.
In late summer the Japanese knotweed flowers creating clusters of ‘spiky’ stems that are covered in small creamy-white flowers. These are an excellent source of nectar for insects.
The rhizomes are the extensive underground part of the plant ‘The roots’. They are made up of knots, or ‘nodes’, that are dark brown in colour and leathery in texture. The rhizomes snap easily ‘like a carrot’ and underneath the bark, the rhizome is bright orange or yellow.
Inside the rhizome is a central core that can be dark brown or orange in colour and somethimes it has a yellow outer ring. Young rhizome is very soft and white. The nodes are usually spaced approximately one or two centimetres apart and often small white roots or buds emerge from the knots. Each node has the potential to become a new plant when cut, for example by digging the knotweed up.
Knotweed can grow in any type of soil and can grow up to twenty centimetres a day. Certain herbicides may affect the appearance of knotweed, for example stunting its growth.
Japanese knotweed flowers in the later summer with small creamy-white blossoms that are approximately 0.5 centimetres wide and form clustered ‘spikes’ around the foliage.
Crown buds are round in shape and sit at the base of the older stems. They form in early spring and are bright pink/red in colour.
For more information on knotweed and its removal, don’t hesitate to contact us on 0800 389 1911 or visit our contact page.