The shrub was the product of a partnership between supplier Javado, breeder Van Son & Koot BV and will be sold by Burncoose Nurseries from the autumn.
Plant breeder Charles Williams said: "We are delighted. There are some incredible plants in the shortlist and to win this is fantastic.
The flowers of the plant which grows to about 1.5m in height, sport an "appleblossom pink flush" when young, turning pure white as they mature. The variety is relatively compact and slow growing.
In second place was streptocarpus 'Polka-Dot Purple', a houseplant with striking white and purple flowers produced for up to 10 months of the year and exhibited by Dibleys Nurseries.
Salvia 'Love and Wishes', a graceful, arching plant producing rich purple flowers with burgundy calyces from May to October and exhibited by Dysons Nurseries took third place in the contest.
The plants beat a 20-strong shortlist and were announced at the show on Monday.