As increasing evidence links exposure to gardens and gardening to improved mental health and wellbeing, Chris talks to The Garden columnist Lia Leendertz about her own experiences in this field. Meanwhile in the Wisley Glasshouse, strange things are afoot as a green army prepares to invade an abandoned Victorian house. Callum Munro-Faure shares advice on some of the stars of the show, the weird and wonderful aroids or Araceae family. And finally, plant-hunter extraordinaire Roy Lancaster takes us on a tour of his Hampshire garden, chock-full of exotic plants from around the globe.