I have a similar bed in front of my house, facing directly north. I have ferns, both perennial and evergreen, scabious, primulas, heucheras, some ornamental grasses, crocosmia, snowdrops, narcissi and a verbena boriensis (tall but see-through). They would all probably be more floriferous with more sunlight, but they do O.K.
Geranium pheum survives well in a very shady position.