This week's programme is devoted to all things edible. Writer and podcaster Lucy Chamberlain shares expert tips on growing crops in small spaces and hot dry spots. Allotmenteer Ashley Nwokorie finds delight in growing a taste of her native Zimbabwe – covo or African kale. In the latest part of our Hidden Horticulturists series we highlight the story of Robert Thompson, a Victorian writer who help make gardening accessible to the masses. Host Guy Barter shares tips on hedges for allotments and shares some of his growing fails, proving that even the experts sometimes get it wrong. And finally, award-winning food writer Mark Diacono reveals the Far Eastern spice you can grow in your garden.