Big, Bad Botany: The Mysterious Side of Plants (2015)

Every spring, millions of gardeners head outside to spruce up their flower beds, trees, shrubs and vegetable patches, without thinking much about the history – and sometimes toxicity – of some of their plantings. We talk to a man who has researched the unusual side of gardening and find out about some very interesting plants, and how they were cultivated and used in the past as hallucinogens, medicines and tourist attractions