Rachel de Thame joins Monty Don at Longmeadow to add more medicinal planting to the herb garden - especially those that bees love. She also investigates how gardeners can aid honey bee conservation and protect the nation's favourite pollinators. Monty visits a garden in Herefordshire to see a collection of Siberian Iris, which inspires him to create a new Iris patch, adding warmth and splash of colour into his dry garden. The green-fingered experts also discover a garden containing a stunning collection of clematis Montana. Plus, Nick Bailey reveals how to plan, design and build a border fit for any garden, while in Somerset, Carol Klein visits the home of Margery Fish, the writer who exercised a strong influence on the informal style of the cottage garden, before her death in 1969.