Trees need to be pruned for several reasons: to remove dead or dying branches, to maintain shape, to control the size or spread of the tree and to protect your property from damage. Trees must also be pruned at the proper time. The boxelder should be pruned during the dormant season (November to February). The tools required to prune a tree will depend upon the size of the tree and the size of the branches that need to be cut. When trees are mature, their height usually requires the expertise and equipment of a professional. Know your limitations when it comes to pruning mature trees.
Stand back and examine the shape of the tree before doing any pruning; you do not want to destroy the shape of the tree. Determine if the branches you want to remove will maintain the tree's basic shape. Of course if you have a diseased or damaged branch, you have no choice but to remove it.
Locate the branch collar (on the underside of the branch where it meets the trunk) and the branch ridge (on the topside of the branch where it meets the trunk). Cut the branch from the tree (using the appropriate tool, which depends upon the size of the branch) making sure that you do not remove the branch collar or branch ridge. This allows for the wound to heal correctly.
Prune small branches by cutting above a bud that faces the outside of the tree. This will force the new growth to go in that direction. Use this procedure when shortening a branch or twig.
Follow these steps until you have completed pruning the entire tree. Step back after pruning each branch to ensure that you are not drastically altering the shape and beauty of the tree.