Author - James Spice

Our initial interaction with clients usually starts with the subject of Japanese knotweed identification. Photos sent are examined, and sites visited to determine whether the species in question is Japanese knotweed. In some instances it could be a hybrid, or simply a similar looking plant.  We are always happy to do this, however we thought it would be great to provide a guide to the identification of Japanese knotweed. We thought that this would help you to determine for yourself whether the plant is present.  It would also enable you to understand more about the issues associated with the plant and its various treatment methods.

Japanese knotweed emerges in the spring as small asparagus-like shoots that unravel to reveal red/purple leaves and stems.  As the plant matures it forms purple speckled canes that are similar to bamboo. A zigzag leaf structure then emerges from the nodes displaying the familiar shield-shaped leaves.  In the summer Japanese knotweed can reach a height of over 3 metres, with masses of green leaves and clusters of tiny creamy/white flowers.  Yet despite falling back to a crown of broken stems in the the autumn/winter months, the plant will return with renewed vigour the following season. Energy from the growth above ground is drawn back into the root or rhizome in readiness for the spring.

There is a lot to admire about the Japanese knotweed plant, however its resilience is the main reason that it creates problems for people.  The botanist who introduced the species extracted his samples from the side of a volcano.  It’s ability to deal with harsh terrain and put down root network earned the admiration of the railway industry who used it to shore up embankments.  These days it can make it difficult to obtain a mortgage and can prevent you from developing land. For this reason it is useful to understand the basics  of Japanese knotweed identification.

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Download our guide:

How to identify Japanese knotweed

It provides further information on what to look for at various times of the year, problems associated with Japanese knotweed, treatment methods and other useful sources of information.

In recent days, the story of Birmingham couple Nasreen and Sajid Akhtar has made it to many of the UK’s leading publications. Their inability to sell their home because of their neighbour’s Japanese knotweed infestation was first reported in the Sunday Mail, then The Telegraph and The Sun picked up the story the next day. Radio 2’s Jeremy Vine even devoted a segment of his show to it, on which our very own Simon McGuigan offered advice and timelines dealing with the problem.

There is no doubt that it is a dramatic story, Mrs Akhtar is pictured surrounded by Japanese knotweed that trails over her neighbour’s fence. The story has obviously created a great deal of awareness about the plant and the problems that it can cause. However, the trouble is a lot of the information quoted isn’t sensible or accurate: (more…)

Japanese knotweed

It is difficult to think of a plant that has seen more of a reversal in popularity than Japanese knotweed.  It arrived during Queen Victoria’s reign to plaudits and even awards.  Broad heart shaped leaves and the delicate little white flowers soon made it popular with gardeners and horticulturalists, whilst its fast growing root structure and thick bamboo style stems earned the species a role shoring up the coal pits and railway embankments of Europe.

From this auspicious start Fallopia japonica has become a reviled plant, or weed.  Today people are reticent to mention it, and when they do it evokes worry, sometimes fear.  The benefits of this plant have long been forgotten, because it is an example of the introduction of a non-native species that is right up there with the Cane toad in terms of success.  Both had a job to do in their early years, until it was realised that the detriment far outweighed the benefits. (more…)