Pruning is the art of removing old, dead branches to stimulate new growth in plants. Older hedges can be completely restored by pruning them down to the ground. Pruning of old hedges should only be done in the spring to allow plenty of time for new growth and food storage during the spring and summer months. If dealing with large hedges, consider using power hedge shears instead of the traditional manual ones to ensure cleaner cuts in the branches.
Inspect the old hedges for diseases and damaging pests. If any are present treat these issues before pruning or the hedges may not grow back.
Decide whether to rejuvenate the hedges all at once or over a few seasons. If the hedges are trimmed all at once, they will be gone for an entire season, but this method tends to save time. If the hedges are pruned over a few seasons, there will be certain patches that are bare, but the rest of the older growth will still be present.
Trim the hedges back to within inches of the ground, if doing the pruning all at once. If doing it slowly over time, pick a few of the older branches in the hedge and trim those back to the ground. The next year, select a different set of branches, and continue this practice until all the branches have been cut back.
Fertilize the hedges after pruning to provide them with the necessary nutrients to bounce back.