Dry shade is one of the most difficult exposures, since most shade plants require a high degree of moisture. Luckily, however, there are some plants whose needs for sunlight and moisture are both low. Groundcovers, perennials, shrubs and even bulbs and wildflowers are available that will do well in shade, and once established, will not require much water.
Pachysandra is one of the best-known groundcovers for shade and especially useful for planting under evergreen trees. Wild ginger (Asarum canadense), a native groundcover with large round leaves reaching 12 inches, and bugleweed (Ajuga reptans), with purple flowers and green or purple leaves reaching 6 to 12 inches, are two more attractive groundcovers for dry shade. Other possibilities are lily-of-the-valley (Convallaria majalis), which has fragrant white bell-shaped flowers in the spring, and periwinkle (Vinca minor), a low grower that produces lavender flowers in early summer.
Hostas come in a wide variety of foliage colors and sizes, from miniature types to varieties up to 4 feet across. All will perform well in shade and do not demand a lot of water. Two kinds of ferns are particularly tolerant of dry conditions, the Japanese painted fern (Athyrium niponicum) and the Christmas fern (Polystichum acrostichoides). There are many species of cranesbill (Geranium), all of which produce attractive foliage and white, pink, purple or blue flowers and do well in dry spots with dappled sun.
Horticulturist Lindsay Bond Totten recommends the following drought-tolerant shrubs for shade: Carolina allspice (Calycanthus floridus), 6 to 9 feet tall with dark maroon blossoms; snowberry (Symphoricarpos albus), 3 to 6 feet tall with white berry-like fruit; witch hazel (Hamamelis), 15 to 20 feet tall with yellow or orange flowers; and wild hydrangea (Hydrangea arborescens), with a low, round habit and clusters of white flowers. She also recommends two viburnum varieties, blackhaw viburnum (Viburnum prunifolium), 15 feet tall with creamy white flowers; and maple-leaf viburnum (Viburnum acerifolium) 4 to 6 feet tall with black berries and colorful fall foliage.
Bulbs and Wildflowers
Spring-flowering bulbs do well in deciduous shade, since they flower before the leaves appear on the trees, and then go dormant. Like most spring bulbs, they actually prefer a dry exposure during thir dormancy. Summer snowflake (Leucojum aestivum), snowdrops (Galanthus nivalis), early-blooming varieties of daffodils (Narcissus) and squill (Scilla sibirica) are all good spring bulbs for a shady spot.
You might also consider these native spring wildflowers: bloodroot (Sanguinaria canadensis), bluebells (Mertensia virginica), and trout lily (Erythronium americanum), all of which will emerge and flower before the trees have leafed out.