It may surprise you how quickly a hedge becomes overgrown. If a gardener does not giving pruning attention to a hedge at least once a year, the hedge can quickly grow into an unsightly mess. Most hedges benefit from some amount of pruning in late winter or early spring while still dormant. This primes the hedge for neat and controlled growth throughout the growing season. Trim overgrown hedges carefully to bring them back into control.
Remove the oldest and most unsightly branches from the hedge first. Use the pruning shears to clip these branches off cleanly just above the soil level. You can safely remove up to one-third of the entire hedge if necessary.
With the pruning shears, thin areas of the hedge that have congested growth or branches that cross and rub against each other. Remove these branches where they intersect with the next largest branch.
Shape the hedge with the hedge shears to create an even and symmetrical shape. Strive to take off no more than 3 to 4 inches as you shape the hedge on the top, sides and bottom.
Repeat step one the following late winter or early spring. At this time, continue to rejuvenate the hedge by again removing up to one-third of the oldest and most unsightly branches at just above the soil level. Thin and shape the hedge again as well. Repeat each step the following year to finish removing the oldest growth from the hedge. By this time, the hedge should look neat and shapely.
Once the initial pruning is done, perform annual or biannual shaping, trimming and pruning. If you prune the hedge once or twice each year, it will not become overgrown and will need only minor trimming to keep it nicely shaped and healthy.