Hi Toronto Master Gardeners, I have had my amaryllis growing in the garden during the summer. They have very big leaves now. I will soon be bringing them indoors to overwinter them. Can you please tell me how I bring them to flower? Many thanks.
Thank you for this timely question to the Toronto Master Gardeners.
There is some confusion as to how to care for your amaryllis bulb. I have heard conflicting opinions. One says that it is possible to grow them outdoors in the summer and then to over-winter indoors with their full canopy of leaves. Alternatively, the other best practice that is more strongly advocated, is that they need to have their leaves removed and have a dormancy period before they are potted up to re-bloom. The conflicting opinion, it seems, is seeped in a bit of historical and genetic confusion.
There are two different plants that are both commonly called “amaryllis”. The South African native is the true Amaryllis. Amaryllis belladonna, commonly called “Belladonna Lily”, is one genus with only one species that is found in the south-western Cape.
The other plant that is called amaryllis is actually from the genus Hippeastrum. They are native to the tropical and subtropical regions of the Americas from Argentina, north to Mexico and the Caribbean. The Hippeastrum genus comprises around 90 species and over 600 hybrids and cultivars. They are within the Amaryllidaceae family, which also includes two other well-known bulbous crops: Narcissus and Galanthus. The hippeastrum is the common bulb with glorious trumpet flowers in multiple colours that is grown today around the world.
During the 1820s, a British botanist, Dean Herbert (1778–1847), showed that the Amaryllis and Hippeastrum, also known as “Knight’s Star Lily”, were fundamentally different botanically and he assigned them to different genera. Considerable confusion has always surrounded the correct naming of this plant. However, since so many breeders, growers and traders have persisted in referring to the Hippeastrum plant incorrectly as “Amaryllis”, that that is how it has become known.
In the 18th Century, Dutch growers imported the Hippeastrums from South America and started breeding them into the glorious varieties that we now grow. To make matters a bit more confusing, South African breeders have become some of the leading experts in breeding and exporting Hippeastrums, so many of the “amaryllis” bulbs we buy now come from South Africa.
The distinction between whether we are growing a South African plant or a South American plant is important since South African plants mostly do not require a dormancy period, whereas many South American plants do.
For more information, check out these websites:
Wikipedia, Hippeastrum vs. Amaryllis
So having sorted out which genera of plant we are talking about (the Hippeastrum), although continuing to call it an amaryllis, we can answer your question about overwintering your amaryllis bulbs.
Your bulbs needs to have produced at least four leaves over the summer in order to have enough energy to flower. Allow the leaves to wilt by reducing watering and maybe exposing them to a touch of frost. Dig out the amaryllis, and let them dry out for one to two days in a shady spot. Before you move your amaryllis indoors, select only those with healthy leaves and a healthy bulb. Take them to a cool, dark, dry spot (around 15 degrees Celsius) — the basement, or a very protected spot in the garage. Wrap them up in a brown bag or newspaper. Amaryllis need at least an eight to 12 weeks semi-dormant period before setting new blooms.
At the end of November, go and check on them. If they are beginning to sprout, bring them to a sunny window and start watering them again (slowly at first). You will have to wait several more weeks (six to eight weeks) until new buds appear, but I’m sure you will find all your efforts worthwhile.