Overview: Alan Titchmarsh and Joe Swift celebrate optimism in UK horticulture with a look at the Chelsea nurserymen celebrating new-found success. Actor John Challis - Boycie from Only Fools and Horses - joins Alan to talk about his gardening passions, from a love of rambling roses to the romantic influences he brings to his own garden design. Joe visits the city council which has created a stunning floral tribute to the life-saving air ambulance service that brings injured troops to hospital.