Pennsylvania gardens are located in USDA Hardiness Zones of 4 through 7, meaning that it has cold winters and generally moderate summers by temperature comparison. Putting a perennial garden in shady spots is a great way to expand your landscape planting to include those areas that aren't in full sun locations. Perennial planting will mean that it will have many seasons of growth instead of an annual that has only one year of growth. Pennsylvania gardeners have many choices of perennial plants for the shade.
From the lily family, the grape hyacinth (Muscari spp.) is a fragrant, easy to grow perennial. It is particularly good for shady spots and indoor use. The leaves are linear, and depending on the cultivar can be 6 to 10 inches long. Grape hyacinth flowers resemble a grape cluster, and are 6 to 8 inches higher than the foliage; the bloom colors are blue, white or purple. It thrives in USDA Hardiness Zones of 3 through 10. It grows well in partial shade (tolerates full sun too) with well drained soil. Water regularly. Propagate via offsets or seed.
From the primrose family, the primrose (Primula vulgaris) is a semi-evergreen perennial that is grown as an annual. It is a good plant for containers and for indoor use. The leaves can reach 10 inches in length and are fuzzy. The tubular flowers, in many different colors, are in clusters of 1-inch wide individual blooms. It is hardy in USDA Hardiness Zones of 4 through 8. Grow a primrose in partial shade with moisture retentive rich soil. Propagate via division, cuttings or seed.
From the mint family, the carpet bugleweed (Ajuga reptans) is a fast growing perennial. It is good for shady locations and can get 6 to 10 inches high. The leaves are dark green and 3 to 5 inches long. The tubular flowers are in various colors, and in whorls. The individual blooms are one-half inch long. It is hardy in USDA hardiness Zones 4 through 9. It grows in moist well drained soil with partial to full shade lighting conditions. Propagate via stolon separation, cuttings or seed.
From the buttercup family, the wild columbine (Aquilegia canadensis) is an easy to grow perennial that attracts hummingbirds. The bell-like flowers are red and yellow and 1 to 2 inches long. The fern-like leaves are 4 to 6 inches wide. Primrose plants can get 2 feet tall and 1 foot wide. It is hardy in USDA Hardiness Zones 3 through 8. Grow the plant in moist soil in partial shade, full sun or nearly full shade. Propagate via seed or seedlings.
From the dogbane family, the common periwinkle (Vinca minor) is an evergreen, fast-growing easy-to-grow perennial. The leaves are 2 inches long and elliptical in shape. Its flowers are 1 inch wide, funnel-like, and colors vary. It is hardy in USDA Hardiness Zones 4 through 9. Grow a periwinkle in shade or sun with moist soil. Propagate via division.