The idea that the invasive plant ‘problem’ can be reimagined is nothing new. We were contacted some time ago by Royal College of Art MA Textiles student Marina Belintani, who was focusing on bio-design and had chosen Japanese knotweed as the subject material for her final year project. Marina was keen to explore the value of Japanese knotweed as a material in its own right and demonstrate how something that is considered potentially harmful waste in some circles can be a valuable raw material in others.
We’ve also been working for some time on our own method of converting knotweed waste into biochar by heating it in the absence of oxygen, a method known as pyrolysis, to produce carbon in the form of charcoal. We won a patent for our method last year and now we’re exploring how to scale up the solution to deal with all our knotweed waste, and potentially everyone else’s, thereby locking away thousands of tonnes of carbon scavenged by the plant during its lifetime.
This weekend, the Financial Times investigated further this idea of rethinking invasive plants in an article exploring how Japanese knotweed is being used as a renewable raw material for furniture and textiles. As well as Marina Belintani’s work producing bioplastics and natural dyes, London-based designers Brigitte Kock and Irene Roca Moracia have used knotweed to make tiles, while minimalist French designer Samy Rio has made a bench and table from the invasive plant’s canes, described as “amazingly light and strong.”
We’ve contributed to such projects closer to home too. Knotweed material we excavated from a customer’s property has been used to create a garden bar at a home near our offices - a popular talking point among guests!
Making use of renewable raw materials that are unwanted and abundant undoubtedly makes sense, but care should be taken around removing and using such plants due to the obvious risks of causing spread - and also the potential downside of bestowing value on a material which should ideally be eradicated. Although some reports are exaggerated, Japanese knotweed does cause damage to property, is very difficult to remove and in countries like the UK, it outcompetes native flora which has a serious negative effect on the delicate balance of our ecosystems.