Q.Arrowwood viburnum
I live in northern IL and have three 6-yr old viburnum that are 5ft tall x 3ft wide encroaching on evergreen trees near them. Was going to relocate them. Can I split them in half or quarters, or need to leave whole? If I need to leave whole, can I take cuttings from them and start new ones?
Arrowwood Viburnum is capable of growing up to 12 x 12' unless you have a dwarf/compact cultivar. When branches touch the ground, they may root. Look at your shrubs closely for one of these rooted branches on the periphery. That would be a simple way of starting a new plant. I have never heard of one surviving division but nothing would surprise me about this vigorous and hardy shrub. You can cut them down to several inches to dig them out and transplant. If you don't dig it out, it will come back! You may be able to propagate by root cuttings but the usual method is by stem cuttings. Here is the "how to". https://sites.psu.edu/2016hort202/viburnum-propagation/
