I have two that are growing in full sun, so at least this far north it is happy in full sun. I have seen one growing wild in northern Ohio (where I grew up) under high trees on a stream bank (above most flooding, but maybe rare high water.) So it was probably in all day (or almost) shade there. The shaded one was less densely branched than mine, but it was blooming just fine. If your shade is relatively bright, I would imagine that it will be happy there. Here is one of mine just starting to bloom last spring.

Since it is fine is a range of sun exposures, and the pH range from NH to OH is from quite acid to slightly basic, I think this shrub is fairly flexible about growing conditions, though I don't think it likes it too dry.