Organiser Jamie Butterworth has recruited James Wong, Tom Mitchell of Evolution Plants, eight-year-old young gardener of the year George Hassall, James Alexander Sinclair and Andrew Fisher Tomlin as probable speakers. The new £10,000 Grow careers film may premier at the event.
"We want to push the diversity of horticulture," said Wisley trainee Butterworth. "There's a wide spectrum of careers across the industry."
He said Richard Ballard and Steven Dring's "Growing Underground" project beneath the Tube might feature as an example of new ways to work in gardening.
YoungHort was set up in 2013 to promote careers in horticulture. It is now linked to the RHS schools campaign.