There are more than 600 cultivars of Hippeastrum, a genus in the Amaryllidaceae family that is commonly referred to as amaryllis. The flowers of these plants tend to be showy and colorful, beloved throughout the world for their ability to thrive indoors during the gray winter months. Originally native to the Americas, as well as Mexico, Amaryllis flowers are versatile plants that can be used for a variety of purposes.
Once there is no chance of frost, amaryllis bulbs can be planted. Amaryllis bulbs should be planted in moist, well-drained soil with about half of the bulb above the soil surface. A quality, well-drained potting soil will work, or a potting soil that contains an equal combination of peat moss, sand and garden loam. The plant is hardy to USDA zones 9 to 11.
Outdoor amaryllis plants do best in shade or filtered sunlight, while indoor plants should be kept in a bright, indirect sunlight in a low or moderately humid area.
Soil should be kept moist during spring through fall. During winter dormancy, water infrequently for outdoor plants. Indoor plants shouldn't be watered at all during winter dormancy. Avoid over-watering--too much water may cause bulbs to rot.
Fungal disease is rare, but can be a problem with amaryllis plants grown indoors. Help prevent fungal problems by keeping plants at a distance from each other, avoiding high humidity, and keeping water off the leaves. At the first sign of fungus, apply an anti-fungal to keep the problem from getting worse.
Though amaryllis plants are largely pest free, spider mites and thrips can occasionally be a problem. These pests can be removed or reduced by forcefully spraying the plant with water and applying either insecticide or miticide.