Also called night-blooming cactus, cereus cactus (Hylocerus undatus) is a type of climbing cactus grown for its huge, pure white flowers. At maturity, the heavily scented, dinner plate-sized blooms appear every two weeks from midsummer to fall. Each flower puts on a show for one night only. Despite its exotic beauty, cereus cactus is a fast-growing, low-maintenance plant. Cereus cactus is a sun-loving plant that grows outdoors in U.S. Department of Agriculture plant hardiness zones 10 and above.