Viburnum snowball bush is popular and easy to grow. This large shrub grows into an upright dense mound. The 3-inch clusters of snowball flowers start out apple-green and morph to white, eventually fading to a rosy color, as do some hydrangea shrubs. You can cut the flowers to use in displays. An alternate name for this cultivar name is "Sterile," which reflects the fact that this type of snowball bush produces no berries. The leaves are three-lobed and somewhat resemble the leaves of maple trees. Like maple, the leaves can turn reddish-orange in the fall. This shrub has graced gardens since the 1500s. Some uses for snowball bushes in the yard include hedge plants and specimen plants for spring or fall.
- Botanical Name: Viburnum opulus "Roseum" or "Sterile"
- Common Name: Snowball bush, snowball viburnum, eastern snowball, European cranberrybush, European viburnum snowball bush, Guelder rose "Roseum"
- Plant Type: Broadleaf flowering deciduous shrub
- Mature Size: 12 feet
- Sun Exposure: Full sun to part shade
- Soil Type: Loamy
- Soil pH: 6.5 to 7 (tolerates wide range)
- Bloom Time: Spring
- Flower Color: White
- Hardiness Zones: 3, 4, 5, 6, 7, 8
- Native Area: Europe, Northern Africa, Central Asia
How to Grow Snowball Bush Viburnum
You will have to decide the right spot for the snowball bush, as it will grow fairly large yet mostly be valued for its spring flowers and fall color. Select a spot that will provide lots of sun and allow for the mature size of the bush. Often it is set apart in a yard as a specimen plant, such as in the middle of an island bed, or placed at the corner of a foundation planting as a focal point. Once established, the shrub will be low maintenance. It should be fertilized only once per year and you may want to do some pruning.
Plant a snowball bush in spring or fall. You will need to dig a shallow and broad hole that is as deep as the root ball but is two to three times wider. Fill the hole with the removed soil, with the root crown remaining about 2 inches above the soil level. Water the newly planted bush well and place mulch around it about 4 inches deep.
You can cut the flowers to use in floral displays. If you aren't cutting them, pinch off the spent blossoms to encourage new growth.
Like most plants, you may occasionally have to treat this shrub for disease problems or bug infestations, but preventive measures can be taken. For example, it is 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. Aphids are a common problem for the snowball bush. If you notice aphids on the leaves, spray them with Neem oil, an organic insecticide.
The best location for the shrub will be one in full sun, especially in the Northern states. The snowball bush likes at least six hours of sun per day in order to produce the best masses of flowers. A location in partial shade may be advisable for Southern gardeners.
The snowball bush prefers well-drained, loamy soil but it isn't too particular and will grow in many soil types. It tolerates a wide range of soil pH, but slightly acid is best.
Water snowball bush enough to keep its soil evenly moist, as it does not like dry ground. A suggested schedule is weekly, but water more often in extreme heat. Conserve soil moisture by applying a 3-inch layer of landscape mulch around your shrub, which will have the bonus effect of suppressing weeds.
Temperature and Humidity
The snowball bush is hardy in zones 3 through 8, so it will tolerate fairly harsh winters, but may not do as well in extremely hot climates.
Fertilize the plant in spring with a slow-release fertilizer or work compost into the earth around the plant at any time. Fertilizing too much can inhibit the blossoms. If you find it too costly to buy compost at garden centers, it is easy enough to make your own compost.
Varieties of Snowball Bush Viburnum
You may wish to look for these varieties:
- "Compactum" grows to 6 feet tall, about half of the size of the usual snowball bush.
- "Nanum" is a dwarf variety that grows only 2 feet tall and 3 feet wide.
- The species plant Viburnum opulus (European cranberrybush viburnum) bears attractive berries.
- Viburnum carlesii, the highly fragrant Korean spice viburnum, has smaller flower clusters.
Prune lightly if needed (for example, if you are growing it in a tight spot) just after the flowering period is over.
Other Snowball Bush Shrubs
People apparently find the name of "snowball bush" appealing, because several other plants have commandeered it as their own common name, including:
- Hydrangea arborescens "Annabelle" is a classic hydrangea mimicked by the more recent Incrediball hydrangea cultivar.
- Viburnum macrocephalum is 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 different snowball bushes.
- Viburnum x burkwoodii is a smaller type of viburnum (8 to 10 feet tall) that inherited some of the wonderful smell of its parent, Korean spice viburnum.
- Viburnum x carlcephalum is a smaller, vase-shaped hybrid whose parents are V. macrocephalum and V. carlesii, commonly referred to as "fragrant snowball."