In the 2001, the RHS merged with the Northern Horticultural Society, and in doing so acquired the Harlow Carr Gardens in Yorkshire. The Northern Horticultural Society was founded in 1946 to promote and develop the science, art and practice of horticulture, especially referring to the conditions in the North of England. The park originally started out as a 10.5ha lease but has since been expanded to over double that. It has now been extended to 27.5ha.
