Indoors, amaryllis, poinsettias, and Christmas cactus will grow best in a brightly lit, warm (60 to 75 degree) area away from cold drafts. Keeping these plants evenly moist, but not overwatered, is the real key to success. Like most houseplants, poinsettia, amaryllis, and Christmas cactus especially resent staying wet and will rot if kept continuously soggy. The most accurate way to tell if a potted plant needs to be watered is to check the potting soil. When the soil feels dry and the containers feel light when lifted, it is time to water.
To learn more about caring for these plants through the holidays and beyond, read the whole article posted on the Pender Cooperative Extension website: http://pender.ces.ncsu.edu/2012/12/flowers-for-the-holidays/