The 15x12m exhibit will be a show feature in the Great Pavilion. It is also likely to be shown in the floral hall at Gardening Scotland. Wheatley will also exhibit three front gardens at Malvern Spring Festival that he said will be a "horticultural feast".
The pavilion, split this year into "best of British" and "floral continents", has two new exhibitors, Wildegoose Nursery (formerly Bouts Violas) and Wyndford Farm Plants of West Lothian with a Hobbit-inspired display.
Hillier Nurseries will be aiming for a 70th consecutive gold medal with an exhibit of how overseas plants are used in UK gardens. It will be designer Andy McIndoe's 25th time at Chelsea and grower Ricky Dorlay's 50th appearance at the show.
Binny Plants will show a lake and river of cut peonies. Evison will show hanging basket clematis.
Among the 100 nursery exhibitors in the pavilion, the RHS will show an exhibit with the UK Space Agency. The display will showcase a project in which one million children will grow 2kg of rocket seeds returned from a trip into space.
Scotts Miracle-Gro'wers will display a Learning Journey from Compost to Kitchen at the show.
RHS director Sue Biggs said: "The pavilion sometimes seems to get forgotten in the glamour and excitement of the gardens but it's the experience the visitors score the highest."