If you are a plant lover, chances are that someone will give you an amaryllis this Christmas or that you will grab an inexpensive one yourself off a department store display. And chances are that you will be delighted with the result, because what other plant can provide you with lily-sized blooms indoors during the darkest days of the year?
When I say amaryllis, I mean the genus Hippeastrum, not Amaryllis belladonna, which is strictly a garden plant. Although the Hippeastrums also can be used as perennials in zones 9 through 11, blooming in spring there, most of us grow them indoors during winter.
The hard part usually isn’t getting them to bloom, which most of the houseplant ones will do reliably about 6 to 8 weeks after they are planted. But keeping them healthy enough that they will flower again the following winter can be more tricky.
Mail-order bulbs generally are larger than the department store ones and will produce more than one stalk, sometimes with 5 to 7 blooms per stalk. The smaller department store bulbs I’ve bought in the past only made one stalk with 4 flowers, but also had the advantage of being less expensive and often already potted. I grabbed a double white variety for $5 at Wal-Mart recently, which—surprisingly enough—does seem to have two bud stalks on it.
Should you be tempted to buy an amaryllis after it has been marked down, it’s a good idea to peek inside the box first. The bulbs can—and often do—flower and fade in there while waiting for a buyer, and you won’t want one that has already blown.
Go To Pot
If you purchase a mail-order bulb which requires potting, tuck it snugly into a 6 to 8-inch diameter pot which has drainage holes, with no more than 1 to 2 inches between the bulb and the pot wall on all sides. The upper one-third to one-half of the bulb should protrude above the surface of the potting soil. Place the pot on a sunny windowsill or under a grow light and water it only lightly until the bulb begins sending up a bud stalk or stalks. Then you can water it just enough to keep its soil damp.
When the Bloom Is Off
After the flowers fade and the strappy leaves begin to appear, cut the flower stalks off a couple inches above the bulb and treat the amaryllis as you would any other light-loving houseplant. Although some sources recommend fertilizing it about every two weeks at this stage, you’ll probably want to reduce the strength of the plant food you use or wait until spring, since winter feeding tends to encourage the sort of soft growth which causes insect infestations.
You’ll need the bulb to make at least four large leaves to have any hope of blooming again the following winter. During the summer, you can move it outdoors, placing it in a shady location first and gradually moving it out into the sun. However, if you purchased an already potted bulb, determine whether the pot has drainage holes before you take it outside. If it doesn’t, you should make some or transfer the bulb to another container. I’ve learned from bitter experience that a pot without holes can gather too much water from rainfall and rot the bulb.
The Big Sleep
In autumn move the plant to a cool, dark place and stop watering it until the foliage withers. (The preferred temperature during this period is 50 to 55 degrees Fahrenheit, but I haven’t found the plant to be highly picky about that.) Although directions usually specify that the bulb should remain dormant for two to three months, it often will try to "rise and shine" in six weeks or less if its temperature is warmer than the recommended one. When you see a bud starting, bring the plant out to your windowsill or grow light and begin watering it again. Should the amaryllis seem to be "sleeping well," though, you can let it rest for a couple months and attempt to rouse it with warmth, water, and watts six to eight weeks before the date when you would like it to bloom. If you need to repot your bulb, do so just as it is beginning to emerge from dormancy.
Exceptions to the Rule
The Hippeastrum papilio plant I had for several years didn’t require the typical dormant period and usually would begin to bloom indoors in December after experiencing autumn temperatures outdoors until about mid-October. Other evergreen species types reportedly can perform without die-back too, but deciduous species require the leaf-dropping phase. If you want to try the "chill, but don't kill" method of prodding an evergreen variety into bloom, keep the plant at 50 to 55 degrees Fahrenheit for at least a couple months in a bright location before moving it to a warmer one. (Or you can just leave it out for part of autumn as I did, while being careful that it doesn't freeze.)
Hippeastrums grown from seed usually take at least three years to grow large enough to bloom and--in my experience--begin flowering in late spring the first time they do so. So you may have to readjust their schedules a bit if you want to turn them into winter wonders!