How to get an amaryllis to rebloom
Wondering what to do with that amaryllis you received as a gift?
Their enormous flowers and quick rate of growth make amaryllis (Hippeastrum) highly popular plants. And these giant bulbs are very easy to grow, maintain and encourage to rebloom.
Amaryllis (Hippeastrum) have enjoyed continued success since they were introduced in the second half of the 17th century. There are more than eighty species native to South America. Some fifty large-flowered species and hybrids derived from Hippeastrum vittatum, H. reginae and H. x johnsonii are available on the market. Miniature hybrids derived from Hippeastrum gracilis have been introduced more recently, along with double-flowering hybrids.
The spectacular blooms are borne at the top of a hollow, fleshy stem 45 to 90 cm tall, and last two to three weeks. The inflorescence contains four to five scentless, trumpet-shaped flowers, each 15 to 20 cm in diameter. The flower embryo is already inside the bulb when you purchase it, so it is important to choose good-sized bulbs. A large bulb may produce two or even three floral stalks. Miniature varieties produce two to four flower stalks, 35 to 50 cm tall. Bulbs that already have a beard of roots will do better from the start. The leaves appear while the plant is in bloom or shortly afterward.
Amaryllis are grown in containers. Plant the bulb in a pot made of porous material, like terracotta, just slightly larger in diameter than the bulb. Commercial potting soil for indoor plants can be used, with a bit of sand added for good drainage. Plant the bulb up to its neck, leaving the top third exposed. If you don’t plan to plant the bulb as soon as you bring it home, keep it in a cool spot. By planting bulbs two to three weeks apart, you can have a succession of blooms. It takes about six to eight weeks for a bulb to bloom after it is planted. Once planted, an amaryllis does not like to be repotted. After three or four years, or when necessary, you can replenish some of the soil after the blooms have faded, being careful not to disturb the roots.
Water often enough to keep the soil slightly damp. The flower stalk will appear within four to six weeks. At that point, move the bulb into a warm, sunny spot (24 to 26°C) until the first flowers open. Depending on the hybrid, the flower stalks can be up to 45 cm tall or even more. To extend the blooming period, keep the plant in a cool spot (15 to 18°C). Cut off the flower stalk 5 cm above the base after the plant has finished blooming, being careful not to damage the leaves.
The care provided during the growing period will influence the formation of the next flower bud. Move the plant to a warmer spot (21°C) and feed it every other week with all-purpose fertilizer (20-20-20 or 20-10-20, at half strength) during the growing period, until July. Then switch to a fertilizer high in phosphorous and potassium for the rest of the growing period. Keep your amaryllis in a sunny spot or outdoors in summer.
The rest period begins in September. Gradually cut back on watering until the leaves have dried, then cut them off at the bulb. Water the bulb one last time, then store it in a cool place (12-15°C), out of direct sunlight, for ten to twelve weeks. Do not water it during that time.
Once the rest period is complete, the flowering cycle will recommence. When the flower bud starts to appear, move the amaryllis into a warm, sunny spot (21°C). Resume watering, and it will rebloom in three to five weeks. Do not over-water the bulb, to avoid having it rot. When in bloom, an amaryllis prefers cool temperatures (18-20°C), does not need to be fertilized.
Amaryllis may be propagated by removing the new bulbs that form at the base of the parent bulb. These plants are rarely started from seed because it takes several years for them to bloom and their colours are unpredictable because of hybridization. They are easy to grow, and a great way to have a succession of lovely blooms indoors all winter long. They are especially popular with children.
Based on an article by Gabriel Gauthier in Quatre-Temps magazine, vol. 23, no.1.