 The garden was extensively enlarged during the early years of the 20th century under the stewardship of David Tannock.The garden forms part of Dunedin's Town Belt, a green belt surrounding the inner city, and covers a total of .In July 2010, the Dunedin Botanic Garden was awarded a rank of "Garden of International Significance" by the New Zealand Gardens Trust, becoming one of only five gardens nationwide to be awarded this honour.