Many plants and trees growing throughout Vancouver and the Lower Mainland were imported from other parts of the continent and from points across the Pacific. Examples include the monkey puzzle tree , the Japanese Maple , and various flowering exotics, such as magnolias , azaleas , and rhododendrons . Some species imported from harsher climates in Eastern Canada or Europe have grown to immense sizes. The native Douglas Maple can also attain a tremendous size. Many of the city's streets are lined with flowering varieties of Japanese cherry trees donated from the 1930s onward by the government of Japan. These flower for several weeks in early spring each year, an occasion celebrated by the Vancouver Cherry Blossom Festival . Other streets are lined with flowering chestnut, horse chestnut , and other decorative shade trees.