If it alternates bog and concrete along the line, plant Hosta in the bog and do potted on the concrete.

Before doing anything try to amend the soil. If it sets like concrete it needs more humus and more gritty matter to improve both the texture and the drainage. So as much good compost, leaf mould or even well composted lawn mowings as you can rustle up, and some grit or coarse sand as well. These will even out the moisture holding and prevent the clay particles from setting into lumps. Its worth missing a planting season if necessary to get this right. Even piling your lawn mowings on it over the winter will make a difference.

Then hostas, ferns, lily of the valley, Epimediums, some varieties of perennial geranium, Sarcococca confusa (sweet box) ,
(Look at Long Acre Plants website for more ideas and suggested varieties (shad gardens are their speciality.)