The Linn County Extension Hortline has had several calls this past week asking about how to save and care for amaryllis bulbs — those beautiful showy holiday favorites. It can be done but the key to repeat blooms is proper care.
Once the amaryllis blooms fade, cut off the flower stalk, leaving 1 to 2 inches above the bulb. Don’t cut the foliage; that’s what the bulb uses to replenish itself for next year’s bloom. Place the plant in a sunny window and water only when the soil surface is dry. Fertilize every two to four weeks with a water-soluble houseplant fertilizer.
In late May, relocate the amaryllis plant outdoors, making sure to harden it off first. To harden off any plant, initially place it outside in a shady, protected area. After two or three days, gradually expose plant to longer periods of direct sunlight. Once the amaryllis is hardened, dig a hole and set the pot into the ground in a sunny location and continue to water during dry weather. Make a note on a calendar to fertilize twice a month through July. In mid-September, bring amaryllis back inside and leave it in a sunny window.
To force blooming, you have to induce dormancy and expose the amaryllis to temperatures of 50 to 55 degrees for a minimum of eight to 10 weeks. To induce dormancy, move plant into a cool, semidark location in late September and withhold water. Once the foliage turns brown, cut off leaves and place bulb in a 50 to 55 degree location for at least eight to 10 weeks. After cooling, start the growth cycle again by watering bulb and placing it in a well-lit, 70 to 75 degrees location. Keep potting soil moist, but not wet, until growth appears, hopefully followed by beautiful blooms.
It’s frustrating to go through all this care, only to have your amaryllis produce foliage again but no blooms. There are several possibilities on why this may happen. Perhaps the amaryllis didn’t store enough food preserves in its bulb over the spring and summer months. This would give you a lovely green plant because there is enough energy stored for leaves but not enough for flowers. Or the bulb wasn’t exposed to the proper temperatures (50 to 55 degrees) for the proper time (eight to 10 weeks) in fall. Warmer temperatures and the flower won’t develop.
You can leave your amaryllis in the same pot for three to four years, but if you’d like to change pots, the best time to repot is immediately after its cool period before it reblooms. For specific questions about amaryllis or other holiday plants, call the Linn County Extension Hortline at (319) 447-0647.
Lisa Slattery is an Iowa State University Extension Linn County Master Gardener.