Viburnums may be planted in the spring, but the best time to plant them is in the fall. Dig the planting hole twice as wide and as deep as the rootball. Remove the plant from its container and pull apart or cut any roots that are densely matted. Place the shrub in the hole making certain that the top of the root ball is at, and not below, ground level. If the root ball has burlap wrapped around it, set the plant in the hole, burlap and all. Untie the burlap and roll it back or cut it so that it will be below the surface of the soil. If the roots are wrapped in synthetic material instead of burlap, carefully remove it from the rootball and discard. Remove wires or plastic twine; natural twine can be left to rot. Backfill the hole with soil to the level of the surrounding ground and water thoroughly to provide good soil-to-root contact. Allow an open space the size of a 6-foot-diameter circle for each plant so it won't become overcrowded as it matures.
Amendments In Planting or Transplanting
There are a number of products at the garden center that will help your newly planted or transplanted plants deal better with the stress inherent in the planting process. All healthy plants have beneficial fungi, called mycorrhizal fungi, living on their roots. You can buy these valuable additions to your plant’s ecosystem. See the file describing Using Micorrhizae When Planting.
In addition, there are a number of products such as seaweed, compost tea, and beneficial soil microbes that when added to the planting process will help your newly established plants get going faster. See the file New Technology In Plant Growth Activators
For more information see the file on Planting Shrubs. For planting tools see Hand Tools For Digging and Planting in Yardener’s Tool Shed.