I've installed several shade gardens using these flowers (and others).
These flowers bloom at different times of the year.
Featured on this page is a partial plant list for successful shade gardening.
In Middle GA where I've been gardening for the last 20 years, it's too hot to spend a lot of time outdoors in the full sun. Hence the shade garden assumes a major role in the landscape.
While leaf textures and leaf colour is generally the primary focus of the shade garden, I feel like the blooms are important. With thought given to bloom times, it's possible to have blooms in the shade garden every month of the year.