How and when do you prune berberis?
How and When Do You Prune Berberis
Certified GKH Gardening Expert
You should prune it either in late winter or directly after it flowers.
If it is just a shrub, you can just prune to shape. It has no real need to be pruned for health reason. Just remove any branches that are outside the shape you want with a sharp pair of shears. If it is a hedge, then prune to retain the proper hedge form.