Getting an amaryllis to rebloom is not that difficult… but you have to start just after its stops blooming. Source: International Flower Bulb Centre
Most garden bloggers will probably start writing about getting your amaryllis (Hippeastrum) to rebloom in September, as it starts to sink into dormancy, but they’ve got it backwards. Now, during the plant’s prime growing season, is when you have to work on getting it ready to rebloom. How you treat it in September is just a minor detail.
So, let’s start at the beginning. The amaryllis (Hippeastrum) is a subtropical bulb (zone 8) usually grown as a houseplant. Amaryllis bulbs are generally sold in November and December (some may still be available in January, but hurry!) so they’ll be ready to bloom for Christmas. This is not actually their natural blooming season. Under normal circumstances, in the Northern Hemisphere at least, they’d probably bloom somewhere between the end of January and the end of March, but the bulbs sold are specially treated to bloom early.
Amaryllis bulbs will flower in their bag or box if you don’t pot them up fast enough! Source: laidbackgardener.com
Getting an amaryllis to bloom the first time is a snap: pot them up and water them and they simply bloom! In fact, they’ll bloom even if you don’t pot them up: unpotted amaryllis bulbs will often bloom in the bag or box they’re sold in if no one plants them on time.
Recharging Their Batteries
An amaryllis will bloom under just about any light condition, which is great news, as that means you can place them anywhere while they flower. Afterwards, though, you’ve got to move them to a more conducive spot. The full sun of a south window is not too much indoors. Think of the bulb as being a battery and the sun as being its source of energy. Flowering has drained the battery, now you need plenty of sun to recharge it.
When flowering is over, you can cut off the flower stalk (unless you want to collect seed, but that’s another story entirely). Let the stalk turn yellow first, however, for as long as it is green, it will be supplying the bulb with energy. Don’t cut off the leaves, though: they are its primary battery chargers!
When the flowers die, move the plant to the sunniest spot you have. Full, blazing sun is not too much! Source: ask.extension.org
Your amaryllis will remain in leaf through the winter, spring, summer and into early fall. During this period the plant is also very eager for fertilizer. Fertilize your plant with each watering, adding the recommended dose of all-purpose or houseplant fertilizer to the water as you go. Regular fertilizing and abundant sun lead to a bigger bulb … and the bigger the bulb, the better the bloom next year.
Long, floppy leaves show the plant is not getting enough light. Put it in a brighter spot if you want to see it bloom again! Source: http://www.flowershopnetwork.com
Your plant will tell you if it is getting enough light or not. Long, narrow, pale green, arching leaves that break easily are not a good sign: the plant is trying to tell you it is suffering from a lack of lack of light and that it will probably not bloom again next year. If, however, the leaves are relatively short, very broad, at least as upright as arched and very dark green, the plant is saying, “I’m thrilled with the growing conditions and I promise to bloom next year.”
Amaryllis bulb hollowed out by a narcissus fly grub. Source: leslieland.com
Should you place your amaryllis outside for the summer? After all, the sun outdoors is far more intense (windows may seem transparent, but they cut off a lot of light!). That depends. You see, the amaryllis has a serious enemy that may be present in your area: the narcissus fly. The bumblebee-like buzzing adult is rarely seen, but if it lays its egg at the top of your bulb, its fat grub of a larva will hollow your bulb out, possibly killing it and certainly eliminating any chance of bloom. If you or your neighbors grow daffodils (Narcissus), the narcissus fly may well be around and is drawn to amaryllis bulbs like a magnet. So delay putting your amaryllis outdoors until daffodil leaves start to yellow. This spells the end of the adult narcissus fly’s season and you can therefore safely put your bulbs outdoors.
Do acclimatize your bulb gradually to outdoor sun by putting it in a shade for a few days, then in partial shade for a few more days before exposing its foliage to full sun. Bring the bulb indoors early in September, well before the first frost.
Dormant … or Not
Depending on the genetic background of your amaryllis, its foliage may start to look ratty by September … or it may not (there are evergreen Hippeastrum species and your plant may have them in its family tree). If the foliage of your plant does start to yellow, stop watering it: it’s telling you it wants to go dormant. When the leaves have died back entirely, cut them off. If yours still look fresh and green, keep watering your plant. It’s saying it wants to keep growing. Most hybrid amaryllis, though, will go dormant in the fall.
Although many authorities recommend you put your bulb in the darkness during its dormancy, in fact, that’s of no importance. Honestly, do you think a wild amaryllis moves to a dark cave during its dormancy? However, with neither leaves nor flowers, the bulb won’t look like much, so don’t hesitate to hide it from view … as long as you remember where you put it!
The same thing goes for temperature. Again, some authorities have you placing the bulb in the fridge while it’s dormant, but that isn’t necessary. Yes, you can place the bulb in a cool but frost-free spot while it is leafless, but you can also keep it at room temperature: it makes no difference. I prefer to put food in my fridge rather than fill it with amaryllis bulbs.
Out Of Dormancy, Into Bloom
A flower bud or new leaves showing (here you can see both) tell you the plant is ready to start another growing—and, hopefully, blooming—season. Source: karenhancock.com
Sometime over the next 2 to 4 months, a flower bud or the points of new leaves will appear at the tip of the bulb, even if it has not been watered in all that time. This is the bulb telling you (amaryllises are very talkative plants!) it’s time to bring it into the light (if you stored it in darkness) and to start watering it. Water gradually at first, then more and more as it begins to grow. If you treated it correctly, it will soon be in flower again. Note though that, as noted at the beginning of this piece, it will likely bloom later in the season than the first time, from late January to late March. In fact, some hybrids will bloom a second or even third time, sometime during the spring or summer. An amaryllis bulb can live and bloom indoors for decades.
So, you can get your amaryllis bulb to rebloom … but don’t wait until fall: the time to stimulate next year’s bloom it is now!