Viburnums, prized for summer blooms and colorful fall foliage and berries, do not all produce large, bright white flower spheres. Fragrant snowball, Viburnum carlcephalum, and European snowball, Viburnum opulus 'Roseum', are two viburnums that will not disappoint those in search of the nodding summer shrub reminiscent of Grandma's backyard. Viburnums are moderately easy to care for. These species thrive as privacy screens, ornamental shrubs or hedges in USDA zones 4 through 8.
Choose a site with full sun and well-draining soil.
Test soil with a home kit for pH levels. The snowball bush prefers raised levels of acidity, in the 5.5 to 6.5 pH range. Contact local university extension experts for recommendations on soil amendment if your pH level is off.
Prepare the bed by incorporating up to 20 percent organic material, such as composted pine bark or well-rotted manure. Till to a depth of 6 inches to loosen the soil and provide nutrients for the shrub.
Dig a hole two to five times as wide as the shrub's root ball. The depth should allow the viburnum to sit on undisturbed soil for best support over time.
Set the snowball bush into the hole. Backfill with prepared soil, firming gently as you go. Be sure the top of the root ball is covered with soil and sits just under the surface. A berm of soil just outside the root ball zone will encourage moisture to remain near the ball for early root development.
Provide adequate water during the first year of establishment. Keep soil evenly moist but not soggy, and provide extra water during dry spells.
Prune the snowball bush in early spring, removing brittle canes and thin branches for best overall shape and appearance. If you plan to cut back the tops of the shrub, do this after blooming, as flowers may suffer from topping of the bush in spring.
Avoid possible insect infestations, leaf spot and mildew issues with good sanitation practices. Allow 4 to 10 feet around the snowball bush for good air circulation. Avoid watering over foliage and blooms, as water is one of the primary ways leaf spot and fungus germinate and spread. Remove leaf litter from the base of the bush regularly.