Raised by Lynne Dibley of Dibleys Nurseries and exhibited at Chelsea for the first time, the flowers have yellow lower petals in striking contrast to the baby blue upper petals. The first year that the Plant of the Year competition has been run by the RHS, ‘Harlequin Blue’ was on a shortlist of 20 new plants drawn up by top nurserypeople, breeders and plant experts.

Roy Lancaster led the committee which made the final vote on Monday and the full selection of plants will be on display in The Great Pavilion at Chelsea. Streptocarpus ‘Harlequin Blue’ makes a compact plant with masses of flowers and is available from Dibleys Nurseries. It was by far the favourite plant, according to an RHS spokesman, who said it received 29 votes.

In second place was Gaura lindheimeri 'Ruby Ruby' from Hardy's Cottage Garden Plants, with eight votes, while third was a white flowered, hardy lady's slipper orchid, Cypripedium flavum, from McBeans.