When to Pot an Amaryllis for Christmas Bloom

Here is the problem with the amaryllis on the supermarket shelf in mid-December. You bring it home, you pot it, you wait, and it opens somewhere around Valentine's Day. Nothing went wrong. The bulb was simply started about six weeks too late for the occasion you had in mind.

Iowa State University Extension puts an amaryllis at about six to eight weeks from planting to flower, and recommends potting in early to mid-November for a Christmas bloom. That is the whole trick, and it is why this is worth reading in September rather than in December. The decision that matters is not how you care for the plant. It is the date you put it in the pot.

The calendar, backwards from the day you want flowers

Work back from the date rather than forward from the purchase:

• Flowers for Christmas: pot in the first half of November.
• Flowers for New Year: pot in mid to late November.
• Flowers for the dead stretch of February, which is arguably when you want them more: pot in December, which is what most people accidentally do anyway.

Six to eight weeks is a range and not a promise. Variety matters, and so does the temperature of the room. A bulb in a cool hallway takes longer than the same bulb over a radiator. If the date really matters to you, pot two bulbs two weeks apart and let one of them be right.

So what do you do in September and October?

Buy the bulb, and then leave it alone.

This is the part that feels like doing nothing. Good amaryllis bulbs sell out through October and November, and the ones left in December are the small ones. Bulb size is the single best predictor of how many flower stalks you get, so a bigger bulb is not a luxury purchase here, it is the difference between one stalk and two. Buy now, keep it somewhere cool and dry and dark, and pot it in November.

If you are already ordering spring bulbs this month, add it to that order rather than making a separate trip. Everything else in the cart is going in the ground; this one goes in a paper bag in the cupboard.

Paperwhites are not on the same clock

Paperwhites get lumped in with amaryllis because they both flower indoors in winter, and then people pot them on the same day and wonder why one of them is finished before the other has surfaced.

Paperwhites are much faster. They are a Narcissus, the same genus as the daffodil, and unlike most spring bulbs they need no cold storage period at all. Iowa State's method is to give them two to three weeks somewhere cool and dark to root, then move them to a sunny window once the shoots reach three inches, with flowers following after that. Published estimates for the total vary quite a bit, from around three weeks to twice that, so treat paperwhites as a late-November or December job and amaryllis as the one with the early-November deadline.

The practical version: if you want both on the table at once, the amaryllis goes in first by a comfortable margin.

A note if you have pets

This is worth saying because these are the bulbs that come indoors, at the time of year when everything is at nose height on a side table.

The ASPCA lists amaryllis as toxic to dogs, cats and horses, with lycorine among the toxic principles, and lists vomiting, depression, diarrhea, abdominal pain, drooling and tremors among the signs. One piece of nomenclature is worth knowing here, because it trips up a lot of plant lists: the bulb sold as an amaryllis at Christmas is almost always a Hippeastrum, not the true Amaryllis that the ASPCA entry is written for. They are close relatives carrying the same family of alkaloids, so the caution transfers even though the name does not.

Narcissus bulbs, paperwhites included, are poisonous too, and the sap causes the rash florists call daffodil itch. Wear gloves if you are handling a tray of them, and put the finished pots somewhere a cat does not sit.

The short version

An amaryllis for Christmas is an early-November job, and if you want a good bulb you buy it now. Paperwhites can wait. And if you miss the window, you have not really missed anything: a pot of flowers in February beats a pot of flowers in a month that already has plenty going on.