Brian Cox and Robin Ince leaf through the latest tree science with Dame Judi Dench, Tony Kirkham and Tristan Gooley. Dame Judi Dench shares her great love for treekind and describes how over time she has come to create a small woodland in her garden and how meaningful that is for her. Tony Kirkham, former head of Kew Arboretum and Gardens, shares some of the amazing journeys he's been on to find unusual and rare trees around the world. Navigator Tristan Gooley has spent a lifetime learning how to read trees, he explains how nearly everything on a tree can provide clues into the environment around it and how elements like leaf shape and colour can help us to use trees as a compass to navigate our way.

Producer: Melanie Brown