Japanese Knotweed (Fallopia japonica)
Spring
This is when the plants growth is at its fasted, new shoots start to emerge red/purple in colour with a similar look to asparagus spears. At this early stage the leaves are coiled ready to open and are a dark green or red colour.
Summer
During summer, the leaves will have completely opened into a vibrant green heart/shovel shape and can be as large as 20cm in diameter. The height of the plant can reach up 2-3 meters on average. The plant is very attractive at this stage and at the end of summer can grow small clusters of white flowers. The stems are bamboo like in appearance and hollow, the general growth pattern has a distinctive zigzag appearance.
Autumn
In the beginning of Autumn, there will be a very good density of foliage. The leaves on the plant will begin to turn yellow in colour with a distinctive mix of green and yellow leaves within the foliage. The leaves will also be beginning to wilt and the canes will start to darken in colour.
Winter
During late Autumn/Winter the leaves turn yellow/brown, die and fall to the ground. The canes die off and the plant becomes dormant, the dead canes remain standing and can take several years to decompose if left unattended. Dead canes can supress competition from native flora and plants.
DISTINCTIVE IN SHAPE THE LEAVES
The Leaves – Quite a distinctive heart/shovel shape with a point, the leaves grow opposite to each other on the stem in a zigzag formation.
The Rhizome – Japanese Knotweed rhizome gives the same snapping sensation of a carrot when broken in half, the outside is dark brown while the inside is orange/yellow in colour.
Stems – Japanese Knotweed stems have a similar appearance to bamboo; the nodes grow in a zigzag pattern along the stem which is hollow.
