Tips for Proper Tree Pruning

What is the purpose of tree pruning? Is it really necessary? What should I look for while pruning? APRD’s Forestry and Beautification team regularly receives these questions and more from residents curious about how to care for their trees at home. Urban Forestry Land Manager Wendy Pappas is here with answers to those questions! Keep reading to learn more about the reasons for pruning and what you can look for when pruning your own trees.

Why Prune a Tree?

There are many reasons trees should be pruned regularly in order to maintain the best health and physical appearance of the plant. First of all, pruning removes dead or dying branches, as well as branches that have been damaged. The pruning process also involves removing low-hanging branches that are rubbing against each other or growing in a direction that is inconvenient or dangerous. For example, if a branch is growing towards your house or power lines, it will need to be pruned before it reaches the structure.

Codominant Stems

You should prune to rid your tree of codominant stems. You can recognize codominant stems by looking for two or more similarly sized stems emerging from the same location on the main trunk. These should be pruned because as the tree ages, these stems tend to fail more often than central “leader” stems. It’s important to prune codominant stems when the tree is still young and small.

Branch Unions

Be sure to also look at the branch unions on your tree and see if they need to be pruned. A branch union takes place where a branch meets the trunk of the tree. Ideal branch unions should be U-shaped rather than V-shaped. V-shaped branch unions are weak and have a higher likelihood of failure, so you’ll want to prune these as you come across them.

Trees Seal, Not Heal

When pruning, it’s important to remember that trees “heal” differently than humans. When we get a cut or scrape, our bodies replace the lost skin and we will likely be as good as new. However, if a tree gets injured, it only covers injuries by sealing over them in a way that will keep insects and disease from infesting the tree through the wound. Because of this, timing is key when pruning, and it needs to be done before the tree matures.

Timing

The majority of pruning should be performed when the tree is young. If pruning takes place too late in a tree’s life, the tree will have a harder time sealing off the larger surface area. Larger trees require more energy and take longer to seal wounds than smaller trees. Major pruning should also take place in the winter when trees are dormant, unless you are simply removing dead or damaged wood, which can take place in any season.

Pruning Steps

The best method to pruning is a 3-step process. The first cut should be a shallow notch made on the underside of the branch.  It should be .5” to 1.5” deep depending on the size of the branch.  This prevents a falling branch from tearing the trunk tissue as it pulls away from the tree.

Move to the other side of the branch directly across from your first notch and cut all the way through, leaving a stub. Lastly, make a cut to remove the stub. Your final cut should be outside the branch bark ridge and branch collar. This is because most of the sealing tissue is in the branch collar.  If this tissue is disturbed, it will take longer for the tree to seal the cut.

Click through the slideshow above to better understand each step of the pruning process. Using these tips will ensure a happy and healthy tree! Stay tuned for more garden and landscape advice from APRD’s Forestry and Beautification Team.