Why do pink rain lillies flower after rains, but not from being watered? How to make them flower?

Question

We have pink rain lilies (Zephyranthes Carinata) in the garden. In my personal experience, I've found that they always flower, without exception, shortly after rains. However, there are roughly ten totally dry months each year. During this time, even though I water them regularly with well-water, I've never seen them flower. I've tried copious amounts of water, and frequent watering, but to no avail. They seem to depend on rain.

The rains here come at different times each year. We just had a totally unexpected rainstorm in May, causing them to flower. We are inland in southern India. It's very hot here, and the climate is quite dry in the periods when it's not raining.

1. What is it about the rain that makes this plant flower? (No need for excessive details on this.)
2. How can I utilize the answer to #1 to make them flower even when there is no rain?

Answer 1

It's not the rain as such, it's the high humidity when it rains that triggers flowering. As said previously, they need periods of drought and they are bulbs, which means they may repeat flower, but can't be in flower all the time, or whenever you wish them to be, if that is frequently. If you could find a way of raising the humidity of the air around them, that might trigger flowering, and the only way I can think of doing that is by creating a humidity tent over them, or put them in a greenhouse and keep the humidity high in there, as well as watering.