Jul 30, 2019 · Purple Fountain Grass. Snapdragon. Swiss Chard. Strawflower. 1. Calendula. Calendula, Calendula officinalis, aka pot marigold, is actually a tender perennial in warm climates, but it is widely grown as an annual in cool locales. Sow seeds in spring for richly-hued orange, yellow, and peach blossoms right through fall.