This week on Gardeners' World, Monty Don is at RHS Garden Wisley in Surrey. He'll be getting the latest advice about how best to look after orchids, along with some top tips on how to create a mini-meadow from scratch. He's also keen to find out more about alpines with a view to growing some back home at Longmeadow. Carol Klein helps a Britain in Bloom volunteer who's determined to bring colour to the former mining town of Easington Colliery. First time gardener Michael Welsh has begged and borrowed plants from all over to start a community garden. Carol uses her expertise to help him get even more plants for free. Joe Swift gets an early taste of summer colour at the National Botanic Garden of Wales where they're hard at work conserving some of the rarest plants in the world.