Do your coneflowers wilt in Zone 7?
I planted a bunch of coneflowers because they were known to be a tough flower in Zone 4. I was surprised when I saw them droop in the summer sun here; even though they've been watered the evening before. Is that typical for mid-central VA? Poor little darlings, they curl their leaves away from the sun come 1-2:00 p.m.
I planted Yarrow (Achillea)and that seems to tolerate the sun better. How does Coreopsis do? Which perennials take the heat the best?