Our guest for this episode, Alastair Campbell, has long recognised the positive impact of the natural world on his mind, body and spirit. While walking on London's Hampstead Heath, the communicator, writer and strategist opens up about his mental health struggles and how green space helps get him through. It's a tough listen at times, but an important topic that many will relate to.   Hear all about his popular 'tree of the day' posts and his sense of nature being a healer, especially since his breakdown in the 1980s. Alastair also shows us the special tree that marked a turning point for his mental health - and the birth of his first son.