The amaryllis is a tropical perennial plant known for its colorful blooms. Several flowering plant species are called amaryllis, but the amaryllis of Hippeastrum genus is one of the most widely grown in home gardens and produces large, brilliant flowers in a variety of colors. This species of amaryllis grows indoors, or outdoors in the warmer climates of the southern United States. It is readily propagated from existing plant bulbs.
Dig up amaryllis bulbs in the late summer or early fall after the leaves begin to yellow and die. Leave as much root matter attached to the bulbs as possible.
Divide the bulbs. The large original bulbs develop smaller bulbs, called offsets, during the warm growing season. Offsets are approximately a quarter to a third of the size of the mother bulb. Break them or cut them off with a small knife.
Replant the offsets in a garden or in pots. Space offsets in a garden bed approximately 1 foot apart, cover with small amounts of top soil, then cover with a layer of mulch to protect bulbs from cold winter temperatures. In containers, plant the offsets in a slightly acidic, sandy-loam soil mix. Soil mixtures of this type, specifically made to grow bulbs, are available at nurseries and garden centers.
Water the young amaryllis bulbs liberally.
Fertilize amaryllis bulbs in the spring. Apply a low-nitrogen fertilizer, such as 5-10-10 or 6-12-12, to garden beds as soon as new growth appears. Repeat when stems are 6 to 8 inches tall. Use a water-soluble, liquid fertilizer for amaryllis bulbs planted in containers at half the recommended rate every five to six weeks.