Amaryllis grow best in tight spaces so select a container that is about one-inch larger in diameter and twice as tall as the bulb with drainage holes in the bottom. Hold the bulb over the container with the roots dangling to the bottom and add a sterile potting mix. Firm the soil around the roots carefully to avoid damaging them. Leave the top third to half of the bulb visible above the soil.
Put the container in a sink and water thoroughly. When the water has stopped draining, set the plant in a warm, sunny location. As the flower opens move the plant away from direct sunlight and to a cooler location to prolong the bloom period which can last up to one month.
When blooming is complete, the amaryllis plant is still growing. Remove the bloom stalk to prevent the bulb from expending energy on seed formation. Move the container back to the sunny window. When the danger of frost has passed you can begin to gradually expose the plant to the outdoors. First secure the container in an area outdoors with dappled shade. Over time you can move it to a location that receives six hours of full sun each day. Apply a balanced houseplant fertilizer monthly.
Prior to the first frost bring the amaryllis back inside and place it in a dark location. Stop watering it and when the leaves dry cut them off just above the bulb. Allow the bulb to rest for eight to twelve weeks with no water. When new growth appears or when you are ready to force the bloom, relocate the bulb to a sunny window and begin watering and fertilizing regularly. From dormancy to bloom it usually takes four to six weeks. Though amaryllis only require repotting every three to four years, the time to do this is after dormancy. (Cynthia Domenghini)