Question:
An amaryllis bulb saved from a previous year produces leaves, but doesn’t bloom. Why?Answer:
An amaryllis bulb purchased at a garden center or other retail business typically blooms 6 to 8 weeks after the bulb is potted up. In succeeding years, proper cultural practices must be followed to get the bulb to bloom on an annual basis.
After the amaryllis bulb has been potted up and flowered, cut off the flower stalk with a sharp knife. Make the cut 1 to 2 inches above the bulb. Don’t damage the foliage. In order for the bulb to bloom again next season, the plant must replenish its depleted food reserves. The strap-like leaves manufacture food for the plant. Place the plant in a sunny window and water when the soil surface is nearly dry. Fertilize every 2 to 4 weeks with a dilute fertilizer solution.
The amaryllis can be moved outdoors in late May. Harden or acclimate the plant to the outdoors by initially placing it in a shady, protected area. After 2 to 3 days, gradually expose the amaryllis to longer periods of direct sun. The amaryllis should be properly hardened in 7 to 10 days. Once hardened, select a site in partial to full sun. Dig a hole and set the pot into the ground. Outdoors, continue to water the plant during dry weather. Also, continue to fertilize the amaryllis once or twice a month through July. Bring the plant indoors in mid-September. Plants left indoors should be kept in a sunny window.
In order to bloom, amaryllis bulbs must be exposed to temperatures of 50 to 55 degrees Fahrenheit for a minimum of 8 to 10 weeks. This can be accomplished by inducing the plant to go dormant and then storing the dormant bulb at a temperature of 50 to 55 degrees Fahrenheit. To induce dormancy, place the plant in cool, semi-dark location in late September and withhold water. Cut off the foliage when the leaves turn brown. Then place the dormant bulb in a 50 to 55 degree Fahrenheit location for at least 8 to 10 weeks. After the cool requirement has been met, start the growth cycle again by watering the bulb and placing it in a well-lit, 70 to 75 degree Fahrenheit location. Keep the potting soil moist, but not wet, until growth appears. The other option is to place the plant in a well-lit, 50 to 55 degree Fahrenheit location in fall. Maintain the amaryllis as a green plant from fall to early to mid-winter. After the cool requirement has been met, move the plant to a warmer (70 to 75 degree Fahrenheit) location.
More information can be found in this article: All About Amaryllis