Determining which perennials will flower best in shade depends on what kind of shade you have. Partial shade means the plant will get direct sun for at least three hours. Dappled shade means that the area is bright but gets no direct sun. Full shade refers to light conditions along the north side of a house or in a woodland. Many perennials bloom well in part shade.
The first perennial flowers to bloom are hellebores, whose common names, Christmas rose and Lenten rose, reflect their early flowering. They are soon joined by cyclamen, snowdrops, crocus, primroses and pansies.
Early spring brings trilliums and pulmonaria (lungwort) into bloom, followed by bergenia, brunnera, aquilegia (columbine), dicentra (bleeding heart), lily of the valley and polemonium (Jacob's ladder).
Summer offers the most flowers, with blooms on acanthus (bear's breeches), astilbe, bletilla striata (hardy orchid), corydalis, digitalis (foxglove), hardy geranium Rozanne and others, hosta, kirengeshoma, lamium, tiarella and tradescantia. A key factor for summer bloom is regular water. This is especially true if trees are the source of the shade, with the perennials planted within 10 feet of them. The tree roots will take most of the water and nutrients present, so apply extra water during the summer and organic fertiliser each spring to nurture the smaller plants. Mulch to keep moisture levels more even.
In late summer into fall, daylilies continue to bloom in a wide range of colours. Tall background plants such as Japanese anemones, rodgersia and thalictrum (meadow rue) flower now, too, as do ligularia, tricyrtis (toad lily) and symphytum (ornamental comfrey).