Ursula, I have the same problem with Phals, even though I'm very careful not to water them from the top. I think they just don't like the change in temps outside. Mine do fine in the house also, but I use the swamp cooler when things heat up inside. That also helps with the humidity. Of course it ccould be that I over water them while watering the rest when they're all together. I tend to forget them in the house.
