The viburnum propagation process can be done in a couple ways: layering or cuttings. When layering take a low hanging branch and make a small notch with a knife just below a node in the direction of the node. A little slit is all that is necessary. Be sure that the knife is clean. Treat the cut with rooting hormone then stick a toothpick in the wound to hold it open and bury the branch underneath a small amount of soil. Over time roots will form around the wound and you can sever the plant from the mother plant and plant the new plant either in a pot or in the garden. Sometimes branches will begin to root where they meet the ground on their own - without use of the knife. The layering method is reliable but I prefer taking cuttings. With cuttings you can make more viburnums faster.
Taking Viburnum Cuttings
When I take viburnum cuttings I select healthy 3-4 node branches. I cut just below the node but as you can see in the pictures the roots will form along the stem. I treat the cut end of the viburnum branch with rooting hormone then I set it in the rooting media covering both of the bottom nodes. On the top node I left one leaf attached to gather light for photosynthesis.
Finding the balance between moisture loss and photosynthesis is important. Too much leaf surface area on a cutting will cause it to lose water but you want to leave enough that the cutting can gain energy. Cuttings that are sensitive to moisture loss can be trimmed to make smaller leaves and covered with a plastic bag. Don't worry too much, experiment and see what works best!
Once the cuttings are put into the rooting media give them about 2-3 weeks to root. 'Shasta' Viburnum also roots very easily!