Plants that suck metals from the soil can be farmed to make our tech

Farms that grow metal-rich plants are cropping up around the world and promise a greener, less destructive alternative to mining for rare minerals

By Michael Allen

WHEN you cut into a branch of Phyllanthus rufuschaneyi, the sap runs an intensely bright blue-green. That’s the sort of thing that makes plant hunter Anthony van der Ent sit up and take notice. So when he came across this unusual woody shrub at a national park ranger’s station in Malaysian Borneo, he knew he had to investigate further. It turned out that the sap was chock-full of nickel.

Van der Ent, based at the University of Queensland, Australia, is one of several scientists who think plants like this might be a solution to one of the most pressing problems of our age. Demand for many metals has been creeping upwards for years because they are essential ingredients in everyday tech like phones and computers. Our appetite for these metals will soon become even more voracious because they are also needed for green technologies such as wind turbines and the rechargeable batteries in electric cars. Yet mining them is difficult, environmentally damaging and sometimes extremely dangerous.

Could those problems be addressed by growing metals instead? That is what van der Ent believes. We will soon see if he is right as the first metal farms are now springing up in China, Europe and Malaysia. On the face of it, these farms are all-round winners: the profits are tidy, the environmental credentials excellent. So steel yourself for the latest disruptive mining technology: the plant.

The nickel colouring the blue-green sap of the shrub van der Ent discovered is just one of the metals we depend on. Nickel has long been a crucial ingredient in stainless steel. …