New York Times article:
Long Live the Amaryllis!
By C. CLAIBORNE RAYMAY 6, 2008
Q. When my nephew was born 16 years ago, his mother received a white amaryllis, which is about to bloom once again. How long does an amaryllis live?
A. “There are several cultivars, or varieties, of Amaryllis (Hippeastrum) that have been planted in Southern and Caribbean gardens which have thrived and continued to grow for over 100 years, making them heirloom bulbs," said Marc Hachadourian, curator of glasshouse collections at the New York Botanical Garden in the Bronx.
Photo
Credit Victoria Roberts
He said he did not think anyone had calculated how long an individual plant could live, but estimated that an amaryllis would continue to propagate by making more bulbs “for decades, easily.”
Mr. Hachadourian added that some South African relatives of the showy American amaryllis, like Boophane haemanthoides, have bulbs the size of bowling balls, and individual plants that are estimated to be hundreds of years old.
Mature amaryllis bulbs produce new offsets, smaller bulbs from the larger parent bulb, forming clumps capable of producing multiple flower spikes over time. Dividing these clumps is the most reliable way to propagate a favorite plant. They can also be propagated by seed, with the seedlings blooming in three to seven years.
After an amaryllis flowers, it is best to allow the depleted bulb to be replenished by its green leaves in at least four hours of sunlight a day, then let the bulb and roots dry out in the fall and store it in a cool, dry place for 8 to 10 weeks while the new flowers wait inside the bulb.