Cedar hedges are best pruned back in stages beginning in late autumn or early winter. In the spring, prune again when the new growth is just starting.
Cedar hedges can be tricky to prune. Pruning below the green growth can result in the branch never sprouting again. Prune away dead, damaged branches using a sharp pruning shear, saw or lopper. Prune branches that are larger than 1.5 inches thick using a chainsaw, hacksaw or a wood saw. Prune above the branch collar, the bumpy area at the junction of a branch, at a 45-degree angle. The angle prevents fungus and disease by allowing rainwater to better slide off.