The garden was begun by Michel and Gisèle Madre in 1974 in a wild and marshy valley, with ponds created for drainage and initial plantings in 1974-1975. Between 1975 and 1990, nearly 2000 plants were introduced, mainly rhododendrons, azaleas, and other Ericaceae, and in 1990 the garden expanded into an adjacent forest area with the addition of a botanical trail about 1 km long. In 1998 its collections of rhododendrons and azaleas, kalmia, heathers, and Japanese maples were recognized as national collections by the Conservatoire Français des Collections Végétales Spécialisées (CCVS).