The National Botanic Gardens in Glasnevin are a free, year-round haven of global plant collections, including remarkable trees often explored on guided tours. For tonight’s programme, Terry Flanagan visits the Gardens to join guide Eoin O’Reilly, who shows him some of the site’s most spectacular arboreal highlights...

Derek Mooney and guests explore the natural world in all its forms. Listen live every Monday at 10pm on RTÉ Radio 1.