I think (IMO) that choosing the right variety for your climate is critical. I've spent some bucks on Heucheras but while they can be winter-hardy, our summers can do them in.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize that we can't eat money. Cree proverb
The thread "Saving a heuchera/heucherella" in Heucheras forum
They will not tolerate wet feet. Dapple sunlight I think is best or morning sun. In your area maybe nothing after say 11. I have some in more sun but I'm in Washington state on the wet side.