Note: Except to remove a damaged branch, cease pruning two months prior to.
Severe pruning is a method used to prune multi-stem shrubs, including barberry. At least half of the stems are cut down to the ground. When using the severe pruning method for barberry pruning, the oldest stems are cut to encourage new bushy growth.
The remaining stems can be pruned back to the desired height and spread.
Fill the hole with water and let it drain.
Evergreen wintergreen barberry (Berberis julianae), hardy in U.S. Department of Agriculture plant hardiness zones 6 through 9a, may be pruned from late winter through early spring. Sep 21, Barberry should be pruned before the growing season. If tree cover encompasses this plant over time, consider moving the barberry to a full sun location to experience the beautiful leaf coloration fully.
One ornamental shrub stands out as a hardy, beautiful addition to your landscape. Sep 26, Barberry do not require pruning, however respond very well to it. I leave mine alone indefinitely except to remove a damaged, dead or stray branch that is spoiling the look or shape of the plant.
That said, Barberry can be pruned or sheared to maintain a formal shape or hedge, to tidy up the plant, or to reduce size.