Early spring is a great time to prune summer blooming shrubs. Butterfly bush often becomes lank and rangy unless pruned severely, and in Zone 5, it often suffers winter dieback. Solve both problems at once by whacking the entire shrub back to 6 inches above ground line. The photo below shows what a properly pruned butterfly bush will look like after pruning. Don’t worry. It will grow back and bloom beautifully by mid-summer. In fact, it will be more compact and tidy than an unpruned shrub.
You can treat most other summer or fall blooming shrubs the same way. They form flower buds on new growth, so you won’t be sacrificing any blooms. (However, DON’T prune early spring bloomers such as forsythia or lilac now. Wait until they finish flowering to cut them back.) Other examples of shrubs that take well to severe early spring pruning are pink flowered spireas (not the spring-blooming white forms), potentilla, hardy hibiscus, beautyberry, and crape myrtle (in Zones where they suffer winter dieback, and never develop into trees.)
Shrubs grown primarily for attractive stems, such as red-twig dogwood, or colorful foliage, such as purple smoke bush also respond well to severe pruning. Note that pruning the smoke bush will remove it’s smoky plumes, so don’t prune your smoke bush if you want the smoky effect that they provide. The severely pruned shrubs will regrow with renewed vigor and more brilliant color.
So pull out the pruning saw, and start whacking!