Whether your hedge is formal or informal, you have to prune it to remove unhealthy dead wood and to maintain its shape. Trimming the hedge allows the new growing tips to fill in gaps and spaces. Informal hedges sometimes tend to become overgrown, but they are easily lopped back periodically with no ill-effect. Both evergreen and deciduous hedges need to be pruned to maintain shape and plant vigor.
Trim straggly branches and wayward tips. A new hedge may also need corrective shaping and frequent trimming until it grows into the desired form.
Prune the hedge so that it is narrower at the top and wider at the bottom. This allows more sunlight to reach all areas of the hedge, which creates fuller tip growth.
Use manual pruning loppers or pruning shears to make careful cuts in a hedge. Manual hedge shears with long blades offer more control for trimming than do power hedge trimmers.
Once a hedge is properly formed and needs only a quick maintenance touch up, you might want to use a power trimmer to shape the growing tips. Do not use power trimmers for cutting anything larger than tips, because power blades cannot make clean cuts on branches and stems, and they leave ragged splintered ends.
Rejuvenate an older hedge by carefully selecting larger branches that can be pruned away without harming the structure of the plants. If an older hedge has been allowed to become top heavy, removing too much top growth at once can cause an empty space in the center of the plant. Careful selection will open the plant to allow new dense growth.
Clean up all cuttings after you prune the hedge. Rake and remove small branches and leaves.