My three Viburnum Winterthur shrubs have grown extensively since last Spring. I'm looking for advice about trimming them but still hope for blooms next Spring. The berries are nearly gone already from the birds! Thanks in advance!
According to the linked website, limited fall pruning is appropriate, according to your goals for the plants. But it sounds like 'Winterthur' is not expected to get real large (to 6 ft), so little pruning may be needed.
I don't grow V. nudum, but I have two other species. I prune my slow-growing black haw lightly, because it naturally develops the nice horizontal branching I like. I do pretty harsh basal pruning of tall stems of my fast-growing arrow-woods (about one-third of stems per year) to encourage new basal shoots, which helps it maintain a more upright vase shape. I don't know if either of these strategies are appropriate for your shrubs.
Here is a link that might be useful: viburnum nudum 'Winterthur'