When Good Plants Go Bad

Some of my plants became stressed out with too much heat, lack of water/too much water, bug attacks, and/or a combination of all:









Pink Sunburst Canna: since the weather was pretty harsh, I didn't think this was diseased. So, I just cut off the droopy burned leaves. Glad to report that the plant is doing fine now.










Echinacea Purpurea: I am not sure whether this is diseased or I just suck at taking care of this plant. I posted a question on GardenWeb, and hope someone will come to my rescue on this one...