I grew twenty or so species of rain lilies successfully in a place even hotter and dryer than Leo's Phoenix, AZ (the blast furnace of California's Coachella Valley) and learned a few things. The most relevant was flowering was NOT triggered by rain, but instead by the changes in pressure that accompany weather fronts. In most places, rain accompanies pressure changes so I imagine the observation that the lilies bloom after this trigger is what led to their popular name. The town of La Quinta, California has three inches of average annual rainfall, and many years see no rain at all. My rain lilies bloomed without fail in the days after pressure changes, and many had never seen water falling from the sky in all their lives. The naming of "Rain lily" has been confounding correlation with causation. It would be interesting it know if growers on the coast have fewer rain lily flowering events than interior continental growers with the interior's more frequent and greater magnitude pressure changes. I have also found that rain lilies and many other amaryllids will be kicked into flowering with a pulse of Phosphate. I have a salt shaker filled with decomposed bat guano and a big dash of that often does the trick, though it can take a year to see a flower from bud initiation in some species. On another rain lily issue, I now live in Austin, TX where two species are very common. Some older homes have rain lily lawns that they mow like grass and mass flower periodically from spring through fall. Other posts have mentioned taxonomic confusion with rain lilies, but I have never seen such a muddle as with these two very different species. I asked Scott Ogden to sort it out for me and took notes so you'all can go relabel your pots. The giant prairie lily, Zephyranthes drummondii (aka Cooperia pedunculata or Sceptranthes) has very broad grey leaves, perhaps the broadest leaves of any Zephyranthes so it is easy to ID on sight. It flowers most often in the spring. The other common rain lily from this area is also white night flowered (probably shares a pollinator) but it has narrow, more typical leaves and is properly named Zephyranthes chlorosolen (aka Cooperia drummondii). It flowers most often in the fall but both species will flower together, especially in summer. I hope this clears up some confusion, it did for me. Monica Swartz shivering in a week-long freezing rainstorm