Zone 6 really varies. Even hot plants like echinacea need a break from full sun here. We have hot dry wind to go with the clear skies and intense sun. I tell customers to ignore tags that say full sun. I say, that's the full sun they have up in Wisconsin...not here.
Plants that end up in the fully exposed beds look ratty. Their leaves are smaller, blooms are washed out. If they get a break from the sun of at least an hour sometime during the day, they grow much better.
