How Long Does an Amaryllis Bloom?

Amaryllis (Hippeastrum spp.) produce flamboyant blooms over outsize bulbs. The tropical plants grow outdoors only in U.S. Department of Agriculture plant hardiness zones 8 through 10, but they also make a splash as houseplants where they brighten winter holidays. How many times they'll bloom indoors or how long they'll last in the garden depends on how you treat them after they're finished blooming.

Like other bulbs, the amaryllis nurtures next year's plant and bloom as this year's flowers fade. It is also perennial, which means that it lives for three years or longer. How many years your amaryllis lives depends on its ability to gather nutrients, a process fueled by photosynthesis in its leaves.

Unlike many bulbs, amaryllis leaves follow flowers and persist for several months after the plant has bloomed in the spring. Whether outdoors or in a container, do not cut the amaryllis plant's long, straplike leaves until they whither. In this way, you've given the perennial bulb another year of life.

Gift amaryllis bulbs typically arrive eight to 10 weeks before the winter holidays with instructions to begin watering them immediately. Depending on the age of the bulb, it will produce one or more scapes typically topped by three trumpet-shaped flowers in shades of red, pink, white or bicolor combinations. Indoors, with bright light and moderate temperatures, each scape of flowers lasts up to a month. Plants kept in a cool room, around 65 degrees Fahrenheit, bloom longest.

Plant amaryllis bulbs in the garden in September or October in USDA zones 8 through 10. Use purchased bulbs or gift bulbs that have faded. Plant the bulbs in organic, well-draining soil with the wide side down so that the narrow neck sits above the soil.

Beginning when scapes begin growing in February or March, fertilize with a low-nitrogen garden fertilizer such as 5-10-10 or 6-12-12. Work 1 to 1.5 pounds into the soil for every 100-foot of row or for 100 square feet of bed. Fertilize when the bulbs break dormancy, when scapes reach 6 to 8 inches tall and again after the flowers fade in April. Remove faded flower scapes to stop energy-robbing seed formation.

Whether indoors or out, the secret to long-lived amaryllis lies in their ability to build new embryos while their leaves fade throughout the summer. Dormancy allows them to rest before entering the "home stretch" of bloom. After this period of rapid growth, bulbs need a period of 2 to 3 months of dormancy. Stop watering plants and put potted bulbs in a cool, dry basement or plant them with garden bulbs in fall.

Begin watering plants again as they emerge from dormancy in February or March and keep the soil evenly moist as bulbs bloom. Within two to three years, bulbs may produce offsets -- bulblets that, when removed during dormancy and planted in pots or garden, may produce flowers within three to four years, prolonging the bloom of your amaryllis collection.