How to Prune Chinese St John's wort?
Usually little pruning is needed. Lightly shape if necessary, removing dead, damaged or diseased shoots. Prune after flowering.

Chinese St John's wort · Hypericum monogynum
Grows well in moist but well-drained soil in a sunny, sheltered position
Usually little pruning is needed. Lightly shape if necessary, removing dead, damaged or diseased shoots. Prune after flowering.