Kew Gardens was a botanical garden located in London. The Sixth Doctor attempted to bring Peri Brown to Kew Gardens but was diverted to Killingworth in the early 19th century. (TV: The Mark of the Rani) Peri had previously visited Kew Gardens as a child. (PROSE: The Church of Football)
Kew Gardens was used as a prison camp and main control centre by the Gardenizens. (COMIC: The Garden Rebellion)
In 2167, following the 2150s Dalek invasion of Earth, teams of people planted high yield crops at Kew Gardens as part of the recovery effort. Susan visited them there, where she showed David Campbell a device she had created for warming the soil around the planted seeds. (AUDIO: After the Daleks)
In 6012, Donna Noble referred to a terraformed dome on Messaline as "Kew Gardens". (TV: The Doctor's Daughter)