What Is Snowball Bush?
It is important to keep in mind the botanical name of the plant under discussion in this article, because several different bushes share the common name, "snowball bush" (see below). Here I am talking specifically about Viburnum opulus 'Roseum.' The 'Roseum' cultivar name derives from the fact that the flowers, which start out apple-green and morph to white initially, later fade to a rosy color (as do some hydrangea shrubs).
An alternate cultivar name is 'Sterile,' a name reflecting the fact that this is a sterile cultivar: it produces no berries. An alternate common name is "snowball viburnum."
Botanists classify snowball bush as a deciduous shrub.
What Does It Look Like?
These are fairly large shrubs, maturing to 12 feet tall with a similar spread. The leaves are 3-lobed and somewhat resemble the leaves of maple trees. Like the latter, they will furnish you with fall color, which is generally a reddish-orange.
Snowball bush is so called because it bears snowball-like clusters of flowers (white in color, rounded in shape, and about 3 inches in diameter). Blooming time in my zone 5 landscape is May, so I would further classify it as one of the shrubs that bloom in late spring. It thus offers visual interest in the landscape during two seasons: spring (with its display of flowers) and autumn (with its fall foliage).
Another viburnum I grow that has rounded flower clusters is the highly fragrant Korean spice viburnum (Viburnum carlesii). But the flower clusters on the Korean spice type are smaller.
Where Does This Shrub Grow?
Gardeners in planting zones 3-8 can grow snowball bush. The best location for the shrub will be one in full sun (in the North) and with a well-drained, loamy soil (a location in partial shade may be advisable for Southern gardeners).
The species plant, Viburnum opulus (European cranberrybush viburnum) is native to the three continents of the Old World. It bears attractive berries, as does Viburnum trilobum (American cranberrybush viburnum), which is indigenous to North America.
How to Care for Snowball Bushes
Water snowball bush enough to keep its soil evenly moist, as it does not like dry ground. Conserve soil moisture (and suppress weeds, to boot) by applying a 3-inch layer of landscape mulch around your shrub. Prune lightly if needed (for example, if you're growing it in a tight spot) just after flowering.
Fertilize in spring with a slow-release fertilizer or work compost into the earth around the plant at any time. What, you don't have any compost? Read this article to learn how to make your own compost.
It's a good idea to leave space between your snowball bush and other plants to reduce the chance of attack by bacterial leaf spot or powdery mildew. If you notice aphids on the leaves, spray them with Neem oil.
What Other Shrubs Share This Common Name?
People apparently find the name "snowball bush" appealing, because several other plants have commandeered it as their own common name, including:
- Hydrangea arborescens 'Annabelle': a classic hydrangea mimicked by the more recent 'Incrediball' cultivar.
- Viburnum macrocephalum: a very large shrub (it can reach 20 feet tall and wide) with the largest flower heads (up to 8 inches in diameter) among the "snowball bushes."
- Viburnum x burkwoodii: a smaller type of viburnum (8-10 feet tall) that inherited some of the wonderful smell of its parent, Korean spice viburnum.
Uses for snowball bushes include as:
For a Different Look
Not interested in the globular flower heads of snowball bush? A viburnum that gives you a very different look is doublefile viburnum (Viburnum plicatum var. tomentosum 'Mariesii'), with its flat-top flower clusters.