Some suggestions-

Epimedium sp. which make a nice ground cover and can be sheared every winter to remove old foliage. They bloom in spring.

Pulmonaria sp. which bloom in spring, many varieties available, nice foliage with silvery variegation the rest of the growing season, self-seed.

Symphytum grandiflorum- ground cover comfrey, spreads rapidly, blooms in spring, one of the few groundcovers stronger than grass.