The planting and care is the same for amaryllis bulbs, whether you are repotting an old bulb that you've saved or a new one just purchased. However, with the bulbs that you have saved, cut off the old dried leaves before replanting the bulb. Amaryllis can be potted or repotted anytime after the plants have gone through a dormant or rest period which is in fall or winter. Late November is considered to be an ideal time. Plant the bulb in a container that is one to two inches larger in diameter than the base of the bulb.
Potted bulbs thrive under conditions in which they are slightly rootbound.
Containers can be either clay or plastic, and they must have drainage holes in the bottom. This keeps the bulb's nose dry, which helps reduce red blotch infection, a fungal disease. Plant in a well-drained, sterilized potting medium with a soil pH between 6.0 and 6.5. A mixture containing equal parts peat and perlite is excellent. Immediately after planting, thoroughly water the bulb.