All episodes of the potting shed. 25/04/2010. pippa is joined by sarah chesters from rhs rosemoor to answer your gardening questions.. Patricia hewitson was baffled by the mystery shrub which was giving off a 'sickly sweet pong' in her garden in exmouth, devon so she phoned the potting shed on bbc radio devon. home u.k.. But when no one managed to identify the plant mrs hewitson decided to send a picture to experts on the aptly-named 'the potting shed' programme on bbc radio devon..