The Princess Beatrice Garden, with period plants, fruit trees and a fountain, celebrates Queen Victoria's daughter, governor of the island from 1896 until her death in 1944. The garden is a joint effort by English Heritage and BBC Gardeners' World presenter Chris Beardshaw.
"It will contain just about every element of a fashionable Edwardian garden and will transform a fairly unused green space with minimal planting," said an English Heritage representative. "It will complement the Victorian garden at English Heritage's other notable property on the Isle of Wight, Osborne House.
"But while the garden at Osborne House reflects the formality of the Victorian era, Carisbrooke Castle's garden will reflect the Edwardian trend for softer planting."
The design is based on the Edwardian layout of the princess's original private garden at Carisbrooke.
Beardshaw said: "Inspiration can be found wherever you look. Hopefully, visitors will be able to spot where some of my ideas for the garden came from."