Roses have been cultivated at the Montreal Botanical Garden since the 1930s. The Rose Garden was officially inaugurated in 1976. The collection has grown since then to become one of the most significant collections of its kind in North America, particularly in its species diversity. Of the 150-200 species taxonomists identify in the genus, 115 species are included in this collection. All but two of these species successfully overwinter at this USDA zone 4 site with no additional protection other than natural snow cover.