Pruning butterfly bushes is an integral part of maintaining these beautiful flowering shrubs. It is fairly easy to prune a butterfly bush, as they are very tough plants. Butterfly bushes will survive just about any level of pruning they are given at any time of the year. There are, however, pruning techniques that will assure faster growth and better blooms.
When the butterfly bush goes dormant, during the winter of zones five and six, is when the most pruning should take place. During this time pruning butterfly bushes should be done all the way to the ground. This will usually take place some time after the first frost, when the above ground parts of the bush appear dead. In zones eight and up, the butterfly bush will be evergreen, and can be pruned to the ground at any time.