British photographer and set designer Cecil Beaton prided himself on being au courant, but when it came to his country place, Reddish House in Wiltshire, he was as Edwardian as anyone born in 1904 could be. So was the romantic, bamboo-paneled winter garden, created with decorator Felix Harbord, that Beaton added in 1955. “English Baroque proportions, a stone floor in 18th-century French style, Gothic windows that are very Strawberry Hill, and a central fountain that follows the Islamic concept of paradise,” Alexander Hoyle, cult London plantsman, observes of the winter garden, which was featured in AD’s fall 1969 issue. “The combination of elements firmly sets it in an Edwardian Revival idiom.” Given the roughly 20-foot-square footprint, “there was precious little space for growing plants,” he notes of the room, furnished…