It originated in the exotic garden at Kew House formed by Lord Capel of Tewkesbury, enlarged and greatly extended by Princess Augusta, the widow of Frederick, Prince of Wales, for whom Sir William Chambers erected several garden structures, of which the lofty Chinese pagoda erected in 1761 remains. George III enriched the gardens, aided by the skill of William Aiton and of Sir Joseph Banks. The old Kew House was demolished in 1802. The "Dutch House" adjoining was purchased by George III in 1781 as a nursery for the royal children. It is a plain brick structure now known as Kew Palace.
In 1840 the gardens were adopted as a national botanical garden. The gardens were increased to 75 acres, and the pleasure grounds or arboretum extended to 270 acres. There are extensive conservatories, the herbarium and a library.
The Tropical House is the largest surviving Victorian greenhouse in existence.
Kew is important as a repository of seeds, it has one of the most important seedbanks. With the Harvard University Herbaria, and the Australian National Herbarium they cooperate in the IPNI database to produce an authorative source of information on the nomenclature of plants.