Last month's RHS London Plant & Design Show (21-22 February) drew 7,085 visitors, up 20 per cent on 2013.
A "Design Debate Station" by Cityscapes generated a great deal of interest with the #RHSLondon hashtag used 1,045 times throughout the week, meaning 507,000 people were reached. The RHS said this helped "diversify the audience".
RHS "Secret Garden Sundays" are new on 6 April, 4 May, 1 June, 6 July, 3 August, 7 September and 2 November. The events at Lindley Hall are aimed at urban beginner gardeners aged 25-35. Around 1,000 are expected at each show.
The RHS is hoping for a "vibrant market atmosphere" and said the exhibitors must engage in a "confidence-building manner" with the "new audience demographic we are trying to attract".
Food ideas include "serving salads out of a greenhouse, curry from a tropical garden, botanical sorbets and ice creams from a florally dressed van".
The entertainment will include "folk music, botanical painting, gardening demonstrations, have-a-go sessions, flower arranging and performance artists".
The RHS will also hold the annual RHS Great London Plant Fair at Lawrence and Lindley Halls in London on 1-2 April.