Gorgeous puffs of white flowers adorn the snowball bush (Viburnum opulus 'Roseum') in late spring, with the showy white blooms fading to a dusky pink as the blooming season draws to a close. This attractive deciduous shrub, which is hardy in U.S. Department of Agriculture plant hardiness zones 3 to 8, performs well as a single focal point or as a hedge. Plant these eye-catching shrubs in spring after all danger of frost has passed.
Choosing and Preparing the Planting Site
The snowball bush adapts to a variety of soil types and grows well in areas that receive full to partial sun exposure. Once you select a planting site, remove any weeds to clear the area and till the soil to a depth of approximately 12 inches to loosen the soil and break up any compacted areas. According to the National Gardening Association, you only need to add compost to the planting area if your soil is poor; otherwise, you don't need to add any soil amendments before planting the shrub.
Because the snowball bush doesn't tolerate wet feet, be sure to choose a site with well-draining soil. If necessary, test your soil's drainage by digging a 1-foot-deep hole, filling it with water and allowing it to drain. Refill the hole and use a ruler to measure the water's depth. Wait for 15 minutes and remeasure the water. Calculate the amount of water that drains in one hour by taking the amount of water that drained from the hole and multiplying it by four. For example, if the hole drained by 1/2 inch in 15 minutes, the hourly drainage rate equals 2 inches. Anything less than 1 inch indicates poor drainage.
Planting the Snowball Bush
Dig a Hole
Dig a hole that's about as deep as the nursery container the bush is already in and approximately two to three times as wide. The width is important to allow the roots to spread out as the plant becomes established. Because the snowball bush grows roughly 10 to 12 feet tall and wide, allow 12 to 13 feet of space between multiple plants. This gives each bush ample space to grow and minimizes the need to prune the plants to keep their size in check.
Place the Plant in the Hole
Carefully remove the snowball bush from its nursery container and place it in the center of the hole. Fill the hole halfway with the soil, and then water it thoroughly to remove air pockets and help settle the soil around the plant's roots. Once the water is absorbed, fill the hole in completely and water the plant again.
Add a 2- to 3-inch layer of hardwood mulch to the ground surrounding the plant. Keep the mulch from butting against the trunk to prevent disease. This helps minimize weed formation, retain moisture and maintain even soil temperatures, which can reduce plant stress during extremely warm or cool periods.
Although the plant requires minimal maintenance, you should water it regularly for the first few weeks after planting it to maintain evenly moist -- but not wet -- soil. During the summer, water the snowball bush when the weekly rainfall in your area measures less than 1 inch.