The primary reasons for trimming a plum or an apricot are to remove dead wood and to open the tree's canopy to additional light and air, all of which encourages fruit growth and improves the health of the tree. To a lesser degree pruning is also useful for shaping the tree and to restrict the tree's height, although plums and apricots are slow growers and the height of the tree is seldom an issue. Trimming should take place in late winter or early spring, January to March, while the trees are still dormant.
Remove all dead or diseased wood and discard or burn it. Cut dead branches back to the trunk, leaving only the branch ring, or node, on the trunk.
Trim out all branches that rub together or that look as if they are going to cross each other. Branches that touch often have damaged bark, which allows insects and disease to enter the tree.
Cut out all branches that grow sideways through the canopy of the apricot or plum tree. This should open the canopy to additional light and air circulation, which will encourage the development and ripening of fruit later in the season. Again, cut branches back to the trunk, leaving the branch node on the trunk.
Cut the tips of branches in order to shape the tree.