Many people discard amaryllis bulbs after they bloom, but it’s possible—without too much effort—to get a bulb to flower again the following winter.
You will note that after a bulb finishes blooming, it has shrunk to a fraction of its original size. Producing those huge flowers and long leaves depletes the bulb. To flower again, the bulb must “rebuild” by collecting energy from the sun and transforming it into next year’s flowers and foliage. Unless you have a greenhouse or sunroom, you will need to move your bulb outdoors for summer in order for it to rebuild. Light intensity indoors is insufficient.
Care After Bloom
After the flowers on each stem fade, remove the stem, cutting about 3–4 inches above the top of the bulb. Take care to avoid cutting the leaves (if present). Continue to water as needed—i.e., when the top 1/2 inch of the potting mix is dry to the touch. Begin fertilizing the bulb (if the potting mix you use contains fertilizer, skip this step). Use a water-soluble fertilizer formulated for houseplants. Mix and apply the fertilizer according to the instructions on the package.
During or after bloom, an amaryllis bulb will begin to produce foliage. The straplike leaves will grow quite tall and arch outward. It’s not unusual, in low indoor light, for them to flop. You can try to support them. You can rotate the pot occasionally to encourage a more balanced presentation (the leaves, like the flowers, will lean toward the light). But do not cut, trim, or truss up the leaves.
Moving the Bulb Outdoors
After the last frost date in your area (the time when it becomes safe to plant tender annuals like petunias or impatiens in the garden), prepare to move your amaryllis bulb outdoors. There is no rush to do this. You want the weather to be consistently warm and settled.
Moving the bulb outdoors is a process, not a single step. Until now, the bulb has been living as a houseplant. It has no experience of wind, and the light it receives through a window is weak compared to sunlight outdoors. If you move the bulb directly from a windowsill to a sunny, exposed location (on a patio or deck or into the garden), the leaves will be burned by the sun and be damaged by what may feel to you like a gentle breeze. Instead, you must acclimate the bulb to outdoor conditions, a process known as hardening off. Put the bulb in a shady, protected location, and gradually, over the course of a week or two, increase the bulb’s exposure to sun and wind.
Choosing Summer Quarters
To gather and store the energy required to flower again the following winter, an amaryllis needs what all plants need: sunshine, water, and access to nutrients. How much sunshine does the bulb need? In the northern half of the U.S., full sun (six or more hours of direct sunlight each day) is recommended. In the South and Southwest, partial shade (three to four hours of direct sunlight each day) should be sufficient.
When considering where to put your bulb for the summer, you have three options:
– Keep the bulb in its original pot. This is the easy option, but it has significant drawbacks. An amaryllis bulb makes a lot of roots; they will soon fill a small pot. A bulb in confined quarters requires careful attention to watering and fertilizing if it is to return to flowering size. (The slow-release fertilizer that is sometimes included in potting mixes will be exhausted a few months after you pot the bulb.)
– Move the bulb into a larger pot. A 12- to 14-inch-diameter pot is not too large. With more space, the roots will have room to grow and the bulb will need less frequent watering. If you use a potting mix that contains slow-release fertilizer, no fertilizing will be necessary. When transplanting, keep the bulb at the level that it was in its original pot.
– Plant the bulb in the garden. This is the easy-care option. The bulb requires no special attention. It gets the same water (rainfall or irrigation) as the rest of the garden and has access to the nutrients in the soil. When transplanting, keep the bulb at the level that it was in its pot.
Bringing the Bulb Indoors in the Fall
As summer progresses, you should observe that the bulb produces additional leaves and that it increases in size, like a balloon that is being inflated very slowly. These are indications that the bulb is successfully rebuilding itself. Success is not inevitable. Sometimes a bulb fails to thrive. Foliage production is poor, and the bulb does not regain size. Such a bulb is unlikely to flower again and is best discarded.
With the arrival of fall, you need to give thought to bringing the bulb back indoors. An amaryllis bulb left in the ground in Zones 7 and colder will likely be killed by freezing temperatures (a bulb left outdoors in a pot is even more susceptible to winter cold). After being brought back indoors, the bulb needs to be forced into dormancy and given what might be called a resting period of 6–8 weeks. If you want your bulb to flower in winter, you should plan on bringing it indoors some time between late September and mid-October. (For gardeners in cold climates: Standard practice is to bring the bulb in before the first frost, but the bulb will not be injured by a light frost. The foliage may be damaged, but the bulb itself will be fine. Bring it in as soon as you can.)
When the time comes to bring the bulb indoors, dig the bulb from the garden or remove it from its pot. Shake off soil or potting mix that clings to the roots, but leave the roots intact. Also leave the foliage intact and leave any “daughter” bulbs (small bulbs that form at the base of the “mother” bulb) in place. Lay the bulb on newspaper or a piece of cardboard in a place that is out of the weather but well ventilated (a covered porch or a carport, for example) and leave it there for about a week to dry. (Note: If you oversummered your bulb in a pot, you can leave the bulb in the pot, provided the pot is not too large to be placed in a window. Stop watering in the fall, and move the pot indoors, as directed below.)
The Fall Rest
After a week of drying, move the bulb, with the roots and leaves still intact, to a cool location indoors and leave it there for 6–8 weeks. An unheated basement is ideal. A garage in which the temperature does not fall much below 50 degrees F will also serve (the bulb must not be allowed to freeze). If your only option is to store the bulb in a heated space, place the bulb on the floor, which will be much cooler than, say, a table whose surface is 3 feet above the floor. Mark your calendar or set a reminder in your phone to alert you when the bulb’s fall rest is complete.
Some time between mid-November and early December, it will be time to wake the bulb from dormancy. By then the foliage will have withered and dried up. Cut it away with pruning shears, slicing cleanly across the neck, at a point about an inch above the shoulders of the bulb. (With the foliage removed, the bulb should resemble a globe-shaped Christmas ornament.)
If you left the bulb in a pot when you brought it indoors in October, then all you need to do next is to water thoroughly and set it in a sunny window. If you stored your amaryllis as a bare bulb, you will need to pot it. Trim the roots, if necessary, to fit them in the pot you will be using, and follow our instructions on potting an amaryllis bulb.
Two final notes:
– If your bulb produced one or more daughter bulbs during summer and the daughter bulbs remain attached to the mother, you can leave them in place or remove them. The daughters can be discarded or potted separately. Daughter bulbs are rarely large enough to flower, and in our experience, trying to grow a daughter bulb to flowering size is often unrewarding.
– Oversummered amaryllises are typically slower to reawaken and bloom than newly purchased amaryllises. Be patient and go easy on the water as you wait for signs of life. If the bulb is firm, it will eventually grow. And if it bulked up sufficiently during its summer outdoors, it will reward your efforts with a display of the big, colorful flowers for which amaryllises are justly famous.