If every one of the UK's 30 million gardeners planted one medium-sized tree and let it grow to maturity, they would store the same amount of carbon as is produced by driving 284 billion miles (457 billion km), 11 million times around the planet, research by the RHS shows. If every gardener produced 190kg of compost each year, they would save the amount of carbon produced by heating half a million homes for a year.
