A privet hedge is an effective and aesthetically pleasing way to create privacy in your yard. However, if not properly trimmed, a privet hedge suggests to onlookers that the property it's hiding is just as untidy as it is. But it doesn't take a lot of work to return a privet hedge to its former glory. You simply need a sharp pair of pruning shears and an eye for symmetry.
Wait for the right time to trim the hedge. Spring is the best time for the initial shaping. Wait until the hedge sprouts light green leaves. This is a sign that the privet hedge is actively growing and can withstand a trim. However, wait until after the last frost has passed. New growth is quite vulnerable to freezing temperatures.
Plant your two canes in the ground at either end of the hedge.
Determine the height of your hedge. Measure that height on each cane and mark with a permanent marker.
Tie one end of the string to each cane, right at the mark that you have made.
Use the string as a guide to cut a flat top on your privet hedges. Keep your pruning shears parallel to this line as you cut the top of your privet hedge.
Move the canes. Pull up both canes and untie the string. Move the canes to the front of the hedge so they become a guide for cutting its sides. Insert the first cane at roughly 1/3 the length of your privet hedge. Push it through the hedge from the top down so that it is positioned at the desired width of your hedge. Tie the string to it at roughly half of the current height of your hedge. Walk to a point that is roughly 2/3 the length of the hedge. Pull the string until it makes a straight line. Note the spot, plant your next cane there and affix the other end of the string to it.
Use the string as a guide to shape the sides of your privet hedge. Again, cut with your pruning shears parallel to the string.
Make sure the top of your privet hedge is flat. Slightly rounded or pointed hedges deflect snow and can damage the privet hedge.