Amaryllis flowers (Hippeastrum x hybridum) are a familiar sight during the winter holidays with their large, showy flowers. A native of South Africa, this plant blooms in a variety of colors, from white to pink or the traditional red. Amaryllis grows outdoors in U.S. Department of Agriculture plant hardiness zones 8 through 10 and indoors in any climate. An amaryllis bulb generally produces leaves and then a flower stalk that blooms after a period of drought and cool weather. Problems may prevent the plant from producing a flower stalk.
The amaryllis bulb should be planted so the neck is exposed above the soil line. For mass plantings, space the bulbs at least 8 inches apart. An amaryllis bulb that is planted too deep may not produce a flower stalk. To correct the problem of deep planting, lift the bulbs in fall and replant the healthy, firm bulbs at the proper depth.
Amaryllis bulbs prefer a moist, rich soil. But if the soil has too much nitrogen, the plant directs its energy into leaf production and may not produce flowers. To correct the problem, water the plant until the water drains from the bottom of the pot. The excess nitrogen is water-soluble and will run out with the water. You will need to do this a few times before all the nitrogen is gone. Another solution is to allow the leaves to yellow and die back naturally. Once the foliage is dead, cut it back to about 1 inch above the bulb and store the bulb until the following growing season. For bulbs planted outdoors, allow the foliage to die back and stop fertilizing.
When an amaryllis starts growing, it needs bright light that is evenly distributed over the entire plant. Dim light or short days can result in the plant not producing a flower stalk. If the foliage is growing well, rotate the pot every few days to expose the entire plant to the light. If the foliage is weak, increase the light or extend the length of time the plant is in the sun. If the amaryllis is outdoors, consider moving the bulb to an area that receives direct sun for at least six to eight hours daily.
Overly moist soil causes the bulb to rot. It is important to keep the soil moist but not soggy. Check the bulb for signs of water damage, such as a soft, mushy bulb or mold. If the bulb is healthy, remove any standing water in the drip tray and don't water again until the soil is dry to about 2 inches below the surface. If the bulb is planted outdoors, natural rainfall is generally enough to support the amaryllis. Water only during periods of drought.
When an amaryllis blooms, it has used all the energy that was stored in the bulb. It needs the leaves to replenish the nutrients that were spent producing flowers. You can remove the flower stalk once the bloom fades, but the leaves should stay on the plant until they fade naturally. After the leaves turn yellow, they are no longer gathering energy for the bulb. You can cut the yellow leaves about 1 inch above the top of the bulb at this time. If you remove the leaves too soon, the bulb has no energy to produce another bloom the following season.
An amaryllis bulb will not bloom unless it has gone dormant. The soil should be kept almost dry and the bulb stored in the dark and exposed to cool temperatures for about two to three months. The optimum temperature for storage before blooming is 50 to 55 degrees Fahrenheit. If the plant has not started producing leaves, consider putting the bulb in cold storage for about eight weeks and then replanting. The bulb breaks dormancy when temperatures are 70 to 75 F.
- University of California Cooperative Extension Central Coast & South Region: Amaryllis
- University of Florida IFAS Extension: Hippeastrum x Hybridum Amaryllis
- University of Georgia Cobb County Extension Service: Amaryllis
- Mississippi State University Extension Service: Nitrogen Fertility
- Iowa State University Extension and Outreach: Care of the Amaryllis after Flowering
- Jupiterimages/Photos.com/Getty Images