In this week's Gardeners' Corner, Helen Mark talks to botanical artist Diana Oxlade and her husband Eddie about their new book, Fifty Weeds, a visit to Botanic Gardens Palm House is a colour packed sensory experience and Conrad McCormick plants out his dahlias and canna lilies. Also in the programme Mark Patterson takes timely advice from Gareth Austin in his Derry allotment and Ann Fitzsimons joins Helen in the studio with armfuls of plants to talk about how to fill the June gap with colour for the herbaceous border. That's Gardeners' Corner on Saturday morning just after the 9 o'clock news on BBC Radio Ulster.