Montreal Botanical Garden Montreal  (Canada)
Credit: © Jardin botanique de Montréal (Michel Tremblay)

Montreal's garden is big on preservation. Threatened species make up 920 of its 21,000 species and cultivars on 185 acres. The cold climate is contrasted with its 10 exhibition greenhouses (they have 40 more you can't visit) with dedicated houses to arid region plants and a tropical rainforest. There are 20 cultural or themed gardens on display, but the First Nations garden explores native trees and plants and how Native cultures used these for food, medicine and tools.