The common name “snowball bush” causes confusion because it refers to several large, deciduous shrubs, not a single species. The term is broadly applied to plants that produce densely packed, globe-shaped clusters of white flowers resembling snowballs. To accurately identify a “snowball bush,” examine the plant’s specific leaf structure and mature size, as the common name covers plants from different scientific genera.
Identifying the European Snowball Bush
The plant most historically associated with the name “Snowball Bush” is the sterile cultivar Viburnum opulus ‘Roseum’, the European Cranberrybush Viburnum. This large, multi-stemmed shrub has been a popular ornamental since the 16th century, typically reaching 10 to 12 feet in height and spread.
A distinguishing feature is its three-lobed, palmately veined leaves, closely resembling a maple leaf. These deciduous leaves often turn striking shades of reddish-orange in autumn. The flowers of ‘Roseum’ are entirely sterile, producing no fruit, which allows the plant to focus energy on creating impressive, rounded flower clusters.
These flowers emerge in late spring or early summer, initially appearing as lime-green clusters before fading to a creamy white. The large, round flower heads measure three to eight inches in diameter, creating the dense, spherical shape. The shrub’s robust size and dense, rounded form make it a classic choice for hedges or as a standalone specimen plant.
Lookalikes That Share the Common Name
The term “snowball bush” is also applied to Hydrangea arborescens ‘Annabelle’, the Smooth Hydrangea, a popular North American native shrub. While it produces similar white, globe-shaped flower heads, ‘Annabelle’ is smaller, typically maturing to four to six feet. Its leaves are ovate with serrated edges, lacking the distinct lobed structure of the Viburnum opulus.
Another lookalike is the Japanese Snowball, Viburnum plicatum var. plicatum. This shrub is a different species within the same genus as the European type, but it exhibits a distinct, horizontal branching pattern. Its leaves are ovate but have a pleated, wrinkled texture, which clearly differentiates them from the maple-like leaves of the European Cranberrybush.
Pruning timing is a key distinction, based on whether the plant flowers on old or new wood. Viburnum species (European and Japanese Snowballs) bloom on old wood (buds set the previous year). The Smooth Hydrangea, however, blooms on new wood grown in the current season, allowing it to be cut back hard in late winter without sacrificing summer flowers.
Essential Care and Toxicity
Both Viburnum and Hydrangea types of “snowball bush” prefer well-drained, moist soil and thrive in full sun to partial shade.
Pruning
The European Snowball (Viburnum opulus ‘Roseum’) blooms on old wood and is best pruned immediately after flowering in late spring to avoid removing the buds for the following year. In contrast, the Smooth Hydrangea (Hydrangea arborescens ‘Annabelle’) blooms on new wood and should be pruned back in late winter or early spring before new growth begins.
Toxicity
The European Snowball cultivar ‘Roseum’ is sterile and does not produce the mildly toxic red berries found on non-sterile Viburnum opulus. However, the Smooth Hydrangea is classified as toxic to dogs, cats, and horses. All parts of the plant contain cyanogenic glycosides. While severe poisoning is rare, ingestion can cause gastrointestinal upset, including vomiting and diarrhea, in pets and livestock.