The variegated willow (Salix integra "Hakuro Nishiki"), also known as Japanese dappled willow, is a beautiful specimen plant, a large shrub that can reach 6 to 8 feet in height and 6 to 8 feet in spread. It has long, narrow, variegated leaves (hence the name) with green, white and salmon-pink markings. It likes moist to wet soil and full sun to partial shade. Shrubs to grow with a variegated willow need to be tolerant of the same conditions and provide what the willow doesn't: vibrant fall color, evergreen foliage, flowers and low shrubbery.
Dwarf fothergilla (Fothergilla gardenii), a deciduous shrub, grows to only about 4 feet high. It prefers moist soil, produces showy, small white blooms in spring and may re-bloom in fall to coincide with the flaming color of its autumn foliage.
Sweetspire (Itea virginica) likes moist soil and sun to partial shade, so it will grow happily alongside a variegated willow. The sweetspire reaches about 4 feet high and can get up to 9 feet wide, so it needs plenty of room, and in fall will provide a beautiful purplish maroon color on the foliage.
Fatshedera (X Fatshedera lizei), a medium-sized evergreen shrub, will grow to about 5 feet high. It has an almost tropical look to it, as opposed to the forest look of many evergreen shrubs. The tropical feel works well with the breezy variegated willow.
Heavenly bamboo (Nandina domestica) is another evergreen with a tropical look; it also produces lovely red berry clusters. It grows up to about 5 feet high. It can take drier soil than the variegated willow, so planting it slightly uphill or in a raised bed next to the willow will work perfectly.
Japanese camellia (Camellia japonica) fits the bill for showy flowers. In early spring, it produces blooms that can be white, pink or red. Like the variegated willow, it prefers moist soil. It likes partial sun; plant it on the north side of the willow to give it a bit of shade.
Japanese viburnum (Viburnum plicatum) will grow larger than the variegated willow, getting up to 10 feet high and 10 feet wide. It makes a beautiful backdrop to the willow, or, spaced properly, a specimen plant to grow alongside the willow. And the flowers are showy, gorgeous, white balls of bloom that appear in mid-spring. The viburnum grows in full sun to partial shade and will adapt to almost any soil.
Cutleaf stephanandra (Stephanandra incisa var. "Crispa") gets up to about 2 feet tall and will grow from 3 to 6 feet tall. It grows in low, spreading mounds, prefers well-drained soil but will tolerate wetter conditions, and grows in sun to partial shade. It is deciduous and produces small white flowers in spring.
Lingonberry (Vaccinium vitis-idaea) is a diminutive shrub, getting only about 7 inches tall. It spreads and will fill in the area around the willow with glossy, leathery foliage, highlighted by tiny flowers that are pink or white and small, red fruits.