The couple have decided to go green at their home in the Cotswolds, South West England, where they have turned one of their posh barns into a hen house to enable them to produce their own eggs, reported Daily Star.
"Kate is really serious about country living. She's having a vegetable patch designed and converting one of her posh barns into a hen house.
"She wants a compost heap for recycling food waste and loves chatting at the local farmers market. She only eats organic food but wants to grow her own," a source said.
"Jamie feels very strongly about the environment and climate change and he and Kate want to do their bit where they can. It seems she's letting her inner hippy loose on other aspects of her life. The high life just doesn't make her happy any more," the source added.