Thomas Jefferson grew snowball bush, also known as "viburnum opulus" and European cranberrybush viburnum, at Monticello. The old-fashioned hydrangea arborescens, today called "Annabelle," also goes by the snowball bush name. Viburnum blooms in the spring and hydrangea in early summer, but both plants require similar care. Plant snowball bush in fall after dormancy sets in or in spring before growth buds show. Planted correctly, viburnum opulus and hydrangea arborescens produce large, white blooms within a growing season of planting.
Water the shrub's roots well before planting. Allow water to drain so that soil is moist, not heavy and wet. Water "bagged and burlapped" shrubs the night before planting to allow complete drainage.
Dig a hole 1 inch deeper than the root ball is tall. Make it two to three times as wide around. Line the hole with 1 inch of compost or humus.
Pull the shrub out of its container, holding stems as close to the root ball as possible. Do not remove burlap from wrapped plants. Set the shrub in the hole and fill the hole halfway with garden soil. Water deeply. Settle the plant so its crown sits at the same level as in the container or burlap and allow the water to drain completely.
Fill the remaining space in the hole after the water has drained. Untie the burlap on balled shrubs and spread the top open before filling the last half of the hole. Do not pack down soil but do form a "moat" around the stems and water well. Do not water again until the following week unless the weather is very dry. Check the soil about 3 inches below the surface; if it's dry, water the shrub.
Plant viburnum and hydrangeas with about 4 feet of space on all sides when planting hedges. Some larger varieties may need up to 10 feet between shrubs; check spacing requirements on the tag or wrapper. Water deeply but infrequently; plants need 1 inch of water a week.