Amaryllis bulbs should be kept in a temperature-controlled area to prevent freezing during the winter months, and should be kept in an area with good ventilation until planting. If the bulb is purchased in a container, water it lightly only when the soil is dry. When potting an amaryllis bulb, choose a container that is about an inch larger in diameter than the bulb, and use a growing medium that contains organic matter. Allow 1/3 to 1/2 of the bulb to remain uncovered.
Overwatering an amaryllis bulb may cause it to bloom, leaving the bulb susceptible to disease. During the growth period, water the amaryllis bulb when the top 2 inches of soil feel dry, and cut the flower off the plant before it seeds. After growth appears, use a fertilizer that is high in phosphorus on a regular basis. Allow the stalk to remain on the bulb until it becomes yellow.
After blooming, store the bulb in a sunny location indoors and reduce watering until the next blooming period. To force blooming, store the bulb in a dark area indoors, such as a closet, for 12 weeks, and then place the bulb in a sunny location, and water it thoroughly.Learn more about Outdoor Plants & Flowers