The amaryllis (Hippeastrum spp.) is a popular houseplant, but also a rather unusual one in that it is generally sold as a dry bulb you pot up yourself. This makes it special—a sort of hands-on houseplant. Growing an amaryllis makes a splendid project for kids from 6 to 106.
Success the first year is practically guaranteed. Suppliers in the Netherlands (the source of almost all amaryllis bulbs sold in Canada) only ship bulbs that have been checked to ensure they already contain a developing flower stalk, so all you have to do is pot them up and water them a bit. In fact, even if you don’t pot them up, they’ll bloom anyway with, sadly, the flower hidden away in the box they came in!
So the first flowering is easy, but getting amaryllis to bloom again is more complicated. I’ll teach you how to bloom them again and again and again a bit later, but first, let’s get them potted up.
First, pick up the biggest bulb you can get in its category. Large bulbs tend to have more than one flower stalk (up to four, though three is more likely), each bearing three to six enormous flowers. Sure, some amaryllis, notably dwarf ones, have naturally smaller bulbs than others, but even then, the dwarf with the largest bulb will still give you the best results.
Amaryllis bulbs come on the market in October and November and have been specially prepared to bloom at Christmas. This is done through carefully controlled exposure to heat and cold. They’ll usually bloom about three weeks after potting them up, so you should pot them up by early December.
The general rule is to plant them singly in a pot only about 5 cm (2″) wider than the bulb, or three bulbs in a larger pot.
Pre-moisten the growing mix (standard “houseplant mix” will do) and spoon some into the bottom of the pot, enough so the top third of the bulb will be above ground. Do not include a drainage layer of gravel or potshards—amaryllis roots need all the root space they can get.
Now fill in around the bulb with more moist soil and press down lightly. Water and let drain, then place the potted bulb at room temperature in a bright spot, preferably near a window.
Before & During Bloom
Soon a flower stalk will appear from one side of the bulb, and possibly a second from the opposite side (another may appear, but usually later in the year). Water as needed to keep the mix slightly moist and rotate the pot a quarter turn every few days to keep the flower stalk straight, otherwise it may lean towards the light. While the plant is flowering, try to keep it cooler (around 15°C or 59°F)—the flowers will last longer. Even if you keep the plant at room temperature, the display will be outstanding.
Amaryllis come in three categories—those that produce their leaves after they bloom, those that produce them as they bloom and those that are evergreen and therefore have leaves all year. In all three cases, start preparing for the next year’s flowering as soon as the current year’s bloom has faded. Your goal is to plump up the now shrunken bulb (flowering will have taken its toll and the bulb will be smaller and spongier than it originally was). The bigger you can grow it, the better it will bloom.
First, move the plant to the brightest window you have and fertilize regularly with a high phosphorous fertilizer, according to directions. Full sun and sustained fertilizing are needed to recharge this giant bulb’s batteries. Under those conditions the bulb will soon plump up again. The leaves should be wide, dark green and fairly short. If they are long, narrow and pale green, you’re not giving them enough light.
During the summer, you can, if you wish, place your bulb outdoors. Wait until alter the narcissus (daffodil) leaves in your garden have died back before doing so, as the dreaded narcissus fly may find your amaryllis bulb and hollow it out. This pest retreats with the last narcissus leaves, usually by early July, so they can go outdoors then. Acclimatize your bulb slowly over a two-week period until it can tolerate full summer sun. You simply can’t give an amaryllis too much sun.
Many amaryllis bulbs will bloom a second time during the year, in winter, spring or even summer. Just enjoy the added color whenever it occurs, but keep on with your “recharging its batteries” program.
Although many gardeners believe amaryllis bulbs must undergo full fall dormancy, dormancy is, in fact, not really all that important.
Evergreen types of amaryllis like the butterfly amaryllis (Hippeastrum papilio) never go dormant and keep growing right through the fall. Simply bring your amaryllis indoors in September and start giving it cooler temperatures if you can. 12–15°C (54–59°F) is ideal, but if all you can manage are normal home temperatures, don’t worry too much about it. Do not put the bulb in the refrigerator.
In the fall, keep the mix a little on the dry side and stop fertilizing. If your bulb is a dormant type, the leaves will yellow on their own, so cut them off. If they stay green, leave them alone.
As long as your plant holds on to its leaves, keep supplying the most intense sun possible. If it goes dormant and loses its leaves, no light will be needed. In the latter case, you can put it in a dark basement if you want. But you can leave it on the windowsill if you prefer—a dormant plant is indifferent to the presence or absence of light.
Your amaryllis will not likely bloom at Christmas the second time around. That first early bloom was initiated by special treatments back in the Netherlands. Instead, it will probably flower between January and March, which is the normal season for amaryllis blooms.
When you see the bulb bulging outward on one side, a sign that a flower stalk is forming, move the plant to a warmer spot (room temperature), give it light, increase the watering and watch it bloom!
Year after Year
Keep up this treatment year after year, and your amaryllis bulb will bloom again and again. You may need to divide it early in winter every few years since it will produce offsets that will, if you don’t remove them, cause the pot to shatter, but otherwise it prefers to be left alone.
A little sun and fertilizer and a bit of a fall break is not all that much work for such a gorgeous bloom, is it?
Larry Hodgson published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings accessible to the public. This text was originally published in Gardens Central in November 2011.