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Amaryllis Hippeastrum

Amaryllis Photoperiodism…?

Is the Amaryllis (Hippeastrum sp.) a photoperiodic plant? I’ve planted a few bulbs and the buds have shaped now… They’re under florescent light 24-7…I was just wondering if this light condition would affect the next year’s blooms..?

I suspect photoperiodism does have some effect on when an amaryllis blooms, but it is not the only thing to consider, as far as overall blooming goes.

By keeping your amaryllis under light you are increasing its ability to produce needed food — and thus increase leaf size and length — and in the end, bulb size. The larger and more leaves you have on a single amaryllis plant, the more chance you have to have more blossoms when blooming does occur.

You get the same results by placing amaryllis plants right up to your window pane. Amaryllis, used as indoor plants, love direct sunlight, unlike most houseplants.

I have had an amaryllis plant bloom freely without going through a drying out period, but most of the time, this dormant or resting period is necessary to force blooming in the wintertime. That has little to do with the number or quality of blooms, however (and in the end, not much to do with your question).

So to answer your question as succinctly as possible: Yes, I think photoperiodism does have some effect on amaryllis blooming, as far as “when” blooming might occur in our homes or in nature (in the Andes and foothills with the naturally occurring plants), but the actual number and quality of blooms is really determined by how healthy the bulb is — and how healthy the undeveloped flower buds are inside the bulb — and that has a lot to do with the size and length of the leaves.

By the way, not only is photoperiodism a part of the amaryllis’s life cycle, so is the phenomenon of phototropism (note how you usually have to turn the pot of an amaryllis plant in order for the stem to grow straight and not cause the plant to fall over).

Amaryllis Hippeastrum Minerva – Flower timelapse