What a coincidence! I just came on to ask the same question (though I don't know what variety of Viburnum I have). I hope we get an answer!

viburnum macrocephalum is not difficult to root, but it is difficult to keep alive once it is rooted. It's just a bit tricky to get them going. I'm no expert, but I have grown quite a few.

Here's how: Do it now thru mid July.

3 or 4 node cutting from new growth, cut about 1/4" below the bottom node.
With a knife or the sharp part of your clipper, scrape the bottom of the cutting next to the node to wound.
Remove all lower large leaves. Leave only the top two, and one mature leaf.

Dip the cut end in .05% IBA, tap to remove all excess and stick only one node below the surface. Use a seperate stick or other device to make a hole to receive the cutting.
I use 1/3 each peat, perlite, and fine pine bark. But, most any well draining media will do.

mist or place in sealed plastic container.

I do mine in 2" cell packs to conserve space in the Mist box. You can use 32oz cups with drain holes. If condensation quits appearing, water a bit, and mist inside the plastic container. Do not keep too wet.

Once they have developed new roots, in 3-4 months, they can be moved out of the mist, and into simi shade, but be sure to keep them watered. If they show signs of wilting, move them back into mist. When it is evident that they are well rooted, you can give them a half strength shot of liquid root stimulator (6-12-6). Early next spring, they are ready for regular, small amounts of fertilizer.

When transplanting, make sure the receiving media is well watered before starting.

Is it possible to wound, brush on rooting hormone, and ground layer? Pin the wounded branch down, so it stays buried...I like to lay a flat rock over the spot to hold moisture...seems to work better for me. I have rooted other Viburnums in a humidity chamber as TomW has described above..it works.

They are easy to layer. Take one, or several of the lower branches and layer them.

Thanks for all of the advice. I think I will try some from each of the methods described. One question: Millie and Toyon both mention layering. I assume both are talking about ground layering. Does the same time frame for layering apply as for when to take cuttings? Also, has anyone had success with air layering branches and if so when is the best time to do it? TIA

I really never paid much attention to layering, but it appears layering works best during the growing season.

I know these layer easily because I planted one at my parent's place and have potted up numerous new plants due to the mother plant's branches touching the soil and layering.