The palette of plants available for shady gardens is limited compared to full sun species, but there are some alluring options among the shade plants. Unfortunately, many of the most spectacular are disease-prone, high-maintenance “princess"-type plant. Rather than settle for drab green filler, consider some of the shade perennials that are hardy and robust, as well as beautiful.
Found in moist, shady places throughout eastern North America, cardinal flowers are one of the showiest native wildflowers: their scarlet red blossoms appear atop 3-foot stalks in mid-summer and are a favorite of hummingbirds. Cardinal flowers won't tolerate deep shade, but in moderate shade they will seed themselves to form a small colony. They tolerate soggy soil, making them a great choice for a wet, shady spot. USDA zones 2 to 9.
Also known as false forget-me-knot, Brunnera has long-lasting sprays of powder blue flowers in spring which are quite enchanting on their own. But the real treat with Brunnera is the colorful foliage of some of the cultivars. 'Jack Frost', 'Looking Glass' and several others have heart-shaped leaves up to 6 inches in diameter with a glorious silvery hue. Growing about 12 to 18 inches tall, they spread slowly into tidy clumps and are great way to brighten heavily shaded areas. USDA zones 3 to 9.
Another spreading plant for full or partial shade, Ajuga creeps along at a height of just 2 or 3 inches, sending up short flower stalks that look like a tiny purple salvia flower. It is a dainty plant, yet extremely robust and makes great filler around taller shade perennials. Some types of Ajuga also have bronze or dark purplish foliage that creates a striking contrast with the flowers. USDA zones 4 to 10.
Lenten roses, also known by their genus name Hellebore, are among the most stunning flowers for full shade. Also stunning, is the fact that they appear in mid to late winter. In mild climates some bloom so early they are known as Christmas roses. The 2- to 3-inch blossoms droop downward from stalks that are 12 to 18 inches tall and give way to glossy green foliage in spring and summer. Hundreds of colorful cultivars are available. USDA zones 4 to 9.
Comfrey is one of those under-appreciated plants that have a cult-like following among the few gardeners who grow it. It tolerates full sun, but it's much more spectacular in the shade where the leaves become deep green and grow to epic proportions of 2 feet or more. It's an easy way to create a lush, tropical feel in a shady spot, even if soil conditions are abysmal—it actually improves the soil for other plants that are growing nearby. USDA zones 3 to 9.