I can't figure out what's happening to my annual pots. It's been hot, and I've been watering...and things are dying! I stopped watering as much and plants are still dying! The verbena seems especially fragile. ...but only in some of the pots..in others it's fine. Many of the plants...African Daisy (Dimorphotheca aurantiaca ) in particular have stopped blooming. I can't figure out what's going on. Advice??