I have always heard that Nelly Moser is the most shade-tolerant. I plant a few of them last year in a shady location, and they have been showing excellent growth. No blooms yet, but I think that is just because they are not established well-enough yet. A year before I planted the Nelly Mosers, I planted Bourbon and Fireworks in a sunny spot right next to where the Nelly Mosers are, and they just bloomed for the first time this summer (and a lot of blooms too!). I am expecting the Nellies to bloom next year and I will see how the blooms look in shade.