Macharia pulls a piece of paper from his pocket and proudly points to the signature at the bottom. “This paper means I get paid on time for my potatoes, even when the weather is bad,” he said. The precious document is a farming contract Macharia signed in March with the East African Potato Consortium. It says he will sell at least two tonnes of potatoes to food processors each harvesting season for the next two years.

“Thanks to this contract I can earn up to 22,000 Kenyan shillings ($213) per season,” he said.

Recurring drought and sudden cold spells have affected the quality of potatoes and other staples across Kenya.

Peris Mukami, a farmer from Timau village, in Meru County, said her potato yields had declined by over 10 percent in the past two years because “it is either too cold or too hot”.

“The cold damages potato vines with frostbite while heat makes them wilt,” she explained.