Q.When Is Best Time To Prune Judd Vibernum And Still Get A Lot Of Blooms In Following Spring?
I pruned my Judd Vibernum after it bloomed last year. But it grew so much after that, in the summer, that I pruned it again in September. It did not have many blossoms this spring and the blooms I got were lower down on the shrub. Did my pruning cause this unusual lack of blooms? Normally I get lots of blooms all over the shrub.

Certified GKH Gardening Expert
Fall pruning is not recommended for plants because they may not have time to harden off before winter sets in.
Viburnums should be pruned immediately after flowering. Many viburnums form their flower buds the summer before they bloom. So spring pruning will cut off many buds.
Judd is a variant of Koreanspice viburnum.
https://www.gardeningknowhow.com/ornamental/shrubs/viburnum/growing-koreanspice-viburnum.htm