When a juniper begins to grow out into the sidewalk or driveway, there is a great temptation to just cut a straight edge on the plant, giving it the appearance of being a fence or wall and not a natural plant, he says. However, pruning and trimming evergreens to keep them within the bounds of a landscape are accomplished correctly by removing selected branches and twigs back to a branch or trunk. By cutting off a few of the overgrown branches every year, the plant will remain smaller and still maintain its natural shape. The only pruning that should be done on larger evergreen trees is to remove the lower branches, he adds. Topping a tree will not stop its growth, it will only make it look funny and unnatural and encourage insect and disease problems.
Most conifer evergreens look best if there is only one leader, so pick the best and remove the rest.
The tree will look odd for a year or two but will eventually grow out of this awkward stage. Of course the best way to prune an evergreen is not at all. Make sure the plant size will fit the space before buying it, he says. A properly placed shrub or tree needs little, if any, pruning. For more information, contact your local USU County Extension office.