I have huge and long-flowering shrubs.
You won't get a flush of new blooms in spring and summer because a fall pruning will remove all buds.
Jul 20, It is best to prune weigela shrubs in the late spring after they have finished blooming. Trimming weigela bushes right after they bloom will keep you from inadvertently pruning off next year’s flowers.
This is because weigela bloom on wood that it is a year old. The wood that grows this year will bloom next treenotch.barted Reading Time: 3 mins. If the weigelas suffer little dieback, remove a few of the largest, oldest stems on large, well-established plants. Removal of a few large branches in late winter/early spring allows the shrub to bloom in late spring and produce vigorous new flowering shoots for future years.
Late spring or early summer is recommended for weigela pruning- whenever the last flowers have finished blooming. Don’t wait long after they’ve bloomed, either- try to prune the plant immediately.
If you wait too long, the plant won’t have ample time to produce buds for the following spring.