Cannas are spectacular summer bulbs that thrive in the heat of July and August. Sometimes called “canna lilies,” these perennials are unrelated to true lilies.  Flashy and flamboyant, this perennial has distinct, paddle-shape leaves which wrap in ruffles around stems, tapering to refined buds that open into large, rainbow-hued flowers all summer long, even in the heat of late July and early August.