Those areas of deep shade beneath trees or alongside buildings would be the bane of a gardener's existence were it not for flowers that thrive in full shade. These obliging plants have adapted to sunlight shortages and the chilly damp soil they cause. Many shade-tolerant flowers also work well as container plants, especially in window boxes out of the sun.
Eastern Round-Leaved Violet
Cheery yellow eastern round-leaved violets (viola rotundifolia) are low-growing shade perennials. Reaching only 3 to 6 inches in height and spreading up to 9 inches, they grow from rhizomes. Brown stripes mark the yellow petals of flowers atop leafless stalks. The violet's oval-shaped leaves grow in clusters around the stalks.
These very early bloomers flower in March in the St. Louis area, according to the Missouri Botanical Garden. They like full shade and humus-rich, moderately moist to wet soil. Don't let them dry out. While they do best in locations with cool summer temperatures, they will self-sow in most areas and may become invasive. Use them in shady woodland gardens or other areas where they have room to spread.
Available in a range of colors from white to bicolored blues, pink and burgundy, wishbone flower (torenia fournieri) is a 6-inch to 1-foot shade-tolerant annual that blooms from June until frost. While wishbone flower grows in areas with hot summers, it needs protection from the afternoon sun. Plants are happiest with cool summers.
Plant wishbone flowers in partial to full shade and moist rich well-drained soil. Protect their roots with summer mulch to retain soil moisture. In the right locations, wishbone plants will reward you with a long season of abundant multicolored blooms resembling miniature bearded irises. Buy started plants at nurseries and pinch them back to promote bushier growth with more buds. Wait until after the last spring frost before planting, and lift plants before the first autumn frost to pot them for indoor winter bloom.
Spotted touch-me-not (impatiens capensis) bears little resemblance to the shade-loving impatiens walleriana varieties that are a staple in millions of home gardens. An annual reaching up to 5 feet high more than 2 feet wide, spotted touch-me-not produces red-spotted yellow or orange flowers between June and September. They closely resemble nasturtium blooms.
A plant that grows wild in shady Midwestern bogs and woodlands, spotted touch-me-not's ripe seedpods burst at the slightest pressure, broadcasting their contents over a wide area. These plants thrive in shade and rich moist soil. Rain collecting on their blue-green foliage creates a delightful shimmering effect, giving rise to their alternate name of jewelweeds. Effective in beautifying boggy areas, they are excellent additions to woodland and native plant gardens.