How To Trim A Hedge
Depending on your hedge, you may not need to prune it at all.
Informal and mixed hedges usually do best with minimum pruning, other than removing dead or damaged wood. In fact, pruning a hedge that flowers usually does more harm than good. If your hedge is made of bridalweath, spirea, or azalea, doing anything more than cutting out dead or damaged wood will most likely, ruin the lovely natural shape of the plants and also remove forming flowers.
Formal hedges, those trimmed into neat, geometric shapes, add a well groomed appearance to the landscape. Hedges of privet, boxwood, yew, and holly all take well to tight pruning. Flowering hedges, as mentioned above, do not. Also, hedges of juniper, spruce, and other evergreens can be deformed by tight pruning. Cut away the outer branches of these and you will be left with sparse growth that will not grow back well, if at all.
You can prune a hedge using no more than your eye as the measuring tool. But for a really precise formal hedge, you can create a simple, wedge-shaped template with three pieces of wood to define your chosen form.
Alternatively, with the help of a second person, you can also stretch a length of twine across the hedge to check how true your lines are as you cut.
Formal hedges should be wider at the bottom than the top (see illustration). Pruning this way, called battering, encourages light to reach even the lower branches, stimulating new leaf growth and preventing lower branches from dying out—a common problem with hedges. A hedge 6 feet tall, for example, could have a base 3 feet wide and a top just 1 1/2 feet wide.
