i have never had a problem with any of those plants, maybe it was a touch of transplant shock

along with what you have mentioned: heliopsis, joe pye weed, perennial bachelors buttons, sedums, verbena bonares, phlox have all done well in the midst of sweltering days

k

I've never had trouble with any of those either. Were they newly planted or already established?

No . . . the coneflowers hadn't just been transplanted. They are at the back of a perennial border and are even mulched to a depth of about two inches. The leaves curl inwards on my black eyed susans as well. Our house is in the middle of a three acre meadow that has no trees and my flower border faces directly south. I water them once a week in dry weather. This must be just due to the strength of the summer sun here because they perk up in the late afternoon. Thanks for your reply listing "Survivors". I'll keep it for future reference.