56-60" tall. Plant the Gladiolus Mardi Gras Mixture and get a spunky mix of summer color with purple, pink and peach-colored blooms. No guesswork involved--the stunning combination of hues will be the highlight of your summer garden and will make for gorgeous indoor flower arrangements. For an even longer bloom season, plant groups of bulbs in succession two weeks apart. Gladiolus are cold hardy in zones 8-10. In colder areas, lift the bulbs and store in a cool place over the winter.