Providing food for the larvae of sphinx moths, white snowberry (Symphoricarpos albus) provides various birds a source of food with its remarkably white berries. This deciduous shrub makes a good choice for both woodland and hillside gardens, even where soils are dense clay or limestone-based. Grow white snowberry shrubs in U.S. Department of Agriculture Hardiness Zones 3 through 7.
Snowberry grows naturally from Alberta to Nova Scotia in Canada, southward to Minnesota and Virginia in the United States. It grows in mixed woodland settings.
Eventually reaching a mature size of 3 to 6 feet tall and just as wide, white snowberry attains a broadly rounded shape with many twiggy, dense branches that tend to arch and flop. Suckering sprouts from the roots create a thicket-like mass of vegetation. A western form of the shrub (variety laevigatus) tends to grow more upright than the shrubs native to the eastern parts of North America.
The small oval leaves are deep green with a hint of silvery blue sheen in the light. Leaf undersides are heavily hairy or felt-like in texture. They are arranged in opposite pairs on branches. In midsummer, tiny pinkish flowers appear and go unnoticed, but later develop into 1/2-inch sized white fruits (drupes). These berries are snow white and persist into very late autumn, when they finally turn brown. The leaves do not turn colors before dropping off in autumn.
Plant white snowberry in any typical garden soil that has ample drainage of water after irrigation or rains. It tolerates infertile and gravelly soils as well as air pollution and winds. For fuller growth, plant in full to partial sun exposures; it will also grow well in the dappled shade under trees, but likely will stretch its branches toward the source of light.
Whether in a mixed shrub border or as an informal hedge at the edge of a grove of trees, white snowberry shrubs tend to look unkempt after a couple years. Prune away suckering shoots to maintain a singular plant. Consider pruning the main plant back to 6- to 12-inches tall in late winter, and allow it to rejuvenate new, more attractive growth in summer.
Although eaten by birds, the berries will cause vomiting and/or diarrhea in humans if consumed. Calcium oxalate in the fruits and leaves can also cause skin rashes when touched. In humid regions and in damp soil areas lacking abundant sunlight and air flow, anthracnose, rust, powdery mildew and berry rot frequently plague the shrubs.