Impatiens and primrose would look good in the front of the flowers as most varieties do not grow too tall in the shade. Lily of the valley, viola, pansy, bleeding heart, hen and chicks, forget-me-not, daylillies and begonias are a few more plants which bloom in the shade.
Also consider some short varieties of evergreen plants for year-around foliage in gold, lime green or red. If you plant too close to a tree, the plants may not do well. Test them to see what works well for you.
Rose White, author of
Easy Gardens A to Z