Rebecca Day takes responsibility for promotion of the hospice's services and to increase revenue. She will also develop a marketing strategy to boost awareness of the hospice's work.
Her arrival sees the hospice merge its income-generating and communications functions.
The charity is looking to drum up more corporate funding via its newly built St Catherine's Education & Training Centre.
During her five years at the RHS, Day oversaw the charity's bicentenary in 2004 and the RHS ‘Britain in Bloom' campaign.
She has also worked at Help the Aged, Crisis and Scope, and has a background in events management as well as fundraising.