They do like their water! Here, as soon as it quit being rainy and cool, I've had some plants protest the sudden onslaught of heat by having the outer leaves turn yellow. This happens every year here in my heat and usually earlier because it's normally much drier than this year. They are particularly inclined to do it as soon as bloom is over. Many of them seem to take a break from active growing. If those you bought have bloomed and you have them outside in the sun and heat, they might be doing that. If that's what they are doing, some may look pretty sad before there is new active growth later. I just think they take a long siesta post bloom when it's really hot.
