The garden was founded in 1931, in the height of the Great Depression, by mayor Camillien Houde, after years of campaigning by Brother Marie-Victorin; the grounds were designed by Henry Teuscher. It serves to educate the public in general and students of horticulture in particular, as well as to conserve endangered plant species. The grounds are also home to a botanical research institution, and to the Montreal Insectarium; offsite, the Garden staff also administer the Ferme Angrignon educational farm and petting zoo.
With its collection of 22,000 plant species and cultivars, 10 exhibition greenhouses, some thirty thematic gardens, and teams of researchers and activities staff, the Montréal Botanical Garden ranks as one of the world's largest and most spectacular botanical gardens.
While it charges admission, city residents can obtain a pass granting free admission to the outdoor gardens, so many people visit regularly, even if only to sit under the trees. The outdoor areas are also free to everyone between 6 p.m. and nightfall during the summer season (May to September).