You can winter them either in a cool darkish garage or at room temperature with indirect sunlight. Moist soil in winter is OK, but not wet. After they drop their leaves (due to short days), they become really dormant and look dead, but they will leaf out again when the days become longer. Some of the more dwarf, smaller leaved and heavier blooming types will not go dormant as quickly or as completely. You might have to play ball with them by giving them a sunny windowsill if they decide to begin growing again in Jan. or Feb. Pomgranates are very, very easy to grow, and grow easily from seed. They will overwinter outdoors in the ground here in east-central KY, but they die back to the ground each year, just sprouting back in spring like a perennial.