Cornus Alba Sibirica will deal with the poor quality soil and the wet conditions. Not much to look at during the summer but the red stems will stand out during the winter. After a few years, cut back hard to encourage the new stems to regain the colour.

Thanks for that idea and for taking the time to reply, but I think it will grow too high for the position I want it to go. I'll keep looking!

How about Physocarpus? It comes with red or green leaves and flowers in spring. It will take hard pruning.