Ask An Arborist Tree Pruning

Ask an Arborist: The ABC’s of Pruning

By Arbor Day Foundation | March 31, 2017

This is part three of a three-part dormant season pruning series. Catch up on part two, what are the rules of pruning  and watch part one, why do I need to prune.

Tree pruning, trimming, or cutting is an ongoing process throughout the life of your tree. After selecting the right tree and carefully planting it, early pruning is the most important thing you can do for a young tree. Pruning during dormancy is the most common practice.  It results in a vigorous burst of new growth in the spring. It is usually best to wait until the coldest part of winter has passed.

When pruning your trees, there are steps you can follow to ensure you are making the proper cuts and not removing too much off your tree.  Tree experts Andrew Pleninger and Chris Luley created The ABCs Field Guide to Young and Small Tree Pruning to help guide the pruning process. The rules of the ABC’s will tell you where to start, what branches to prune, and when you are finished. Follow these rules to help get you started on your tree pruning.

Step A: Assess the tree

  • How is the tree growing? Is it healthy?
  • What is the setting? Does human activity dictate a desired form for the tree?
  • What species is it? What is its natural form? Is it a ‘shade’ tree or ‘ornamental’ tree? This will dictate how you prune.

Step B: remove Bad branches

  • Start with the three ‘Ds’ – dead, damaged, and diseased.
  • Next, look for branches that are rubbing, or those weakly attached.
  • Look at the tree, and the pile of branches removed so far, if you haven’t reached any of the limits in the ‘five factors,’ continue.

Watch Rules of Pruning for the 5 Factors of Form and Function

 Step C: remove or reduce Competing branches

    • You identified the central leader in Step One; now we want to address any competing branches:
      • Co-dominant stems: it’s best to keep this cut as small as possible, so complete removal is usually best.
      • Competing laterals: these are branches that have a shoot headed upward at the same height as the leader.
    • Next, focus on areas where multiple branches connect to the trunk at the same place. Develop better branch spacing by removing one each year, starting with the largest one first.
    • Next, consider clearance: these temporary branches in the lower third of tree height improve trunk strength, but may need to be shortened.
    • Finally, consider crossing (not rubbing) branches or chances to improve vertical branch spacing. Every pruning cut is a new chance to observe the tree in light of the “five factors;” stop pruning when any of the factors are reached.

If we focus our pruning efforts strategically – with the right tools – we can develop long-lived urban trees. For  more pruning resources visit or University of Florida IFAS Extension.

Have a tree question you want answered? Tweet @arborday with #AskAnArborist and one of our certified arborists will answer.

You Might Also Like


  • Reply David DiFabio April 3, 2017 at 9:20 am

    Do you have gift cards

    • Reply Emily April 3, 2017 at 9:54 am

      Hello David, we do have Stock Certificates available for purchase. These make a great gift for friends, family, coworkers, etc., and can be used to purchase trees from our tree store. Please call our Member Services team toll free, at 888-448-7337, if you are interested in purchasing some! Our team can be reached Monday through Friday, 8am to 7pm, Central Time.

  • Reply MARGO Rosa September 3, 2017 at 7:49 pm

    My two yr. Old maple is over six feet tall. The leaves have black spots e everywhere. What to do now??? I also have another very short tree that I purchased at the same time. It is very short and hardly growing. The leaves are withering away. As soon as the new leave appear they turn wrinkled and brown…Is there a problem here???? Ease answer my questions….’s. Margo Rosa

    • Reply Christine Hutfles September 5, 2017 at 2:46 pm

      Hi Margo, thank you for reaching out. It is very hard to diagnose a tree without seeing it. We suggest reaching out to a local Arborist near you, who will be familiar with common tree issues to your area. Here is a link to find a consulting Arborist:


    Leave a Reply to Christine Hutfles Cancel Reply