A shade garden can seem dark and uninviting, making plant selection crucial to avoid the notorious "Dungeon Effect" commonly found in low light gardens; dank corners, dripping water, complete gloom . Plants most often recommended for shade situations have little color or texture variation, which leads to previously sane gardeners screaming, "I hate ferns! Hate them! Hate them!" Choosing plant species with brightly colored foliage or flowers will easily brighten up a dim area and avoid "The Dungeon Effect".
Brunnera Jack Frost is a low growing shade perennial with heart shaped leaves veined in silver. Looking Glass has foliage almost entirely silver, and both of these varieties bloom as well. The blue flowers are very tiny but born in profusion. Brunnera is hardy in USDA zones 3 through 9. Although this perennial may remain evergreen in mild winters, it will die back to the ground during extreme cold. In zones 3 and 4, a light coating of mulch applied over the crown of the plant in the fall after the foliage dies back will help to increase hardiness.
Campanula persicifolia 'Kelly's Gold'
Campanulas as a species shine as shade plants, but 'Kelly's Gold' truly stands out with its bright yellow unusually shaped foliage. Flowers are an added bonus, light blue in color and contrasting nicely with the leaves. A light trimming after blooming is finished will promote another flush of yellow growth. Removing spent flower buds when the plant is blooming will prolong the flowering period. Campanulas will bloom more luxuriantly if given a location with a few hours of morning sun. These plants are some of the easiest shade perennials to grow. Campanulas in general are tolerant of a wide variety of soils, and are hardy in zones 3 through 9.
Corydalis 'Berry Exciting'
Corydalis 'Berry Exciting' grows fernlike foliage in bright chartreuse and yellow. Clusters of delicate purple tubular flowers appear in spring, and bloom for weeks. The combination of yellow leaves and lavender flowers is stunning. Corydalis is a genus that can disappoint gardeners for its habit of going dormant in summer, however 'Kelly's Gold' does not have this issue and will remain attractive until fall frost. Soil should be rich and loamy, as these plants will not do well in clay. Corydalis is hardy in zones 5 through 9.
Heucheras have a tremendous amount of variation depending on variety. Dark leaved cultivars such as 'Amethyst Myst', 'Raspberry Wine' and 'Obsidian' have shades of deep purple to dark red. Paler forms display foliage color of variegated cream and white, yellow, and gold with orange leaf veins. 'Stoplight' is by far the loudest colored variety of the these, with bright yellow foliage contrasting the orange and red leaf veins. 'Sunspot' is a similar cultivar, and both of these plants add a large amount of color to the shade garden. Heucheras also produce flowers, which add a second show. These plants grow best in well drained, loamy soil. Purple leaved types can tolerate more sun than the paler forms, which can burn in too much heat. Heucheras are hardy in zones 4 through 9.