Sometimes what sells an old house is the thought of restoring it to former glory. Sadly, old plantings do not always come with the same hope. Overgrown, underfed, scraggly, gnarled and bare in spots, an old hedge looks unpromising. Several strategies can improve your chances of restoring an old hedge to its former glory.
The most drastic approach
Remove all dead, diseased, and broken branches with your saw in very early spring. Cut down, then dig out any plants that you know to be completely dead.
Cut all remaining hedge plants to ground level. Do this before the hedge begins to come into leaf, so that natural spring growth surge will go into the formation of new shoots and leaves from the base of the old plants.
Cut off branches rather than trunks of hedge plants if your hedge is composted of evergreen trees. Leave bare trunks and watch for the spring surge to send out new branches.
Fill in the gaps left by dead plants late in the spring, This lets smaller new plants establish their roots during summer growth.
Support possible new growth with compost, fertilizer suitable to your soil and hedge variety, and regular watering. The long growth of old hedge plants may have left surrounding soil short on nutrients.
Monitor new growth. Fertilize in summer, according to directions. Keep well watered until frost. By next spring you can begin making pruning decisions.
A less-drastic but longer-term approach
Remove dead, diseased and broken limbs and plants, as in Section 1. In early spring, select the 1/3 of major branches/trunks that have the largest diameters. Cut these branches to ground level.
Follow feeding and watering strategies suggested in Section. Trim back the remaining branches/plants strictly for appearance and overall shape.
Select a second 1/3 of branches/trunks, based on the thickest diameters, early in the following spring. Cut them back to the ground. You will cut back the final third of old branches/trunks the third spring. You can begin shaping the 2 years of new growth during the third year.