Third episode of the six-part series exploring plant-based natural remedies and beauty treatments. Ethnobotanist James Wong focuses on trees. His recipes for natural tree remedies include a soothing gel for varicose veins made from conkers, a fragrant cologne made from pine, a lotion to tackle head lice and a traditional tea which could help improve memory function. It is a fascinating mix of gardening, science and history, and the volunteers who try James's remedies find out if they can actually help.