Judy Claughton, who left regen charity Groundwork Thames Valley last month after five years as business and comms manager, will focus on the science and learning aspects of horticulture.
‘We want to make plants relevant to everybody, not just the older, more affluent groups traditionally associated with garden shows,' she told PRWeek.
Issues such as climate change, water management and the use of public parks in cities all fall within the RHS's remit, she added.
Reporting to head of press and PR Lynn Beddoe, Claughton will work closely with director of science and learning Dr Simon Thornton Wood, who was appointed in April.
Claughton replaces Eli Smallwood, who moved to PR agency Salt after three years at the RHS.