Many novice gardeners have dug up their Hydrangeas and Rose of Sharon convinced they were dead when no foliage had appeared by mid-May. But summer flowering shrubs remain dormant through early spring and should be pruned at this time. These shrubs bloom on growth from the current year, and need to be pruned before new growth begins. Follow general pruning rules above but also prune back new growth once every spring. The best blooms will come from buds on branches that started during the previous season.
Newer growth is tender, with lighter, shinier bark.
Prune this wood back to leave two or three buds per branch. By pruning back a portion of young growth every year you achieve a foundation of older branches with newer growth at their tips. The shrub will keep its shape from year to year and require minimal mid-season pruning. New branches that emerge from the roots can be pruned to the base or left during the first season in which they appear. During spring prune them back to the same height as the rest of the foundation of growth.