Curator Colin Crosbie said: "It's south-facing so there are perfect conditions. We've always had a Med garden. It was last replanted after the great storm in 1987, so it was time to refresh."
Crosbie said Wisley was "lucky" this winter to lose just 60 trees across the whole site. Good tree management helped to keep the losses down, he explained.
The plants will be from Europe, South Africa and the Americas. Garden manager Matthew Pottage said they were sourced from nurseries that supply RHS Wisley Plant Centre, including Farplants, Liss Forest and Hillier.
RHS Wisley also has a new winter-themed walk featuring Salix, birches, hamamelis and bulbs.