How to Prune a Damaged Magnolia Tree

Betty magnolia tree in bloom, with pink flowers
David Beaulieu

Many a horrified gardener has noticed dead limbs on a specimen tree, such as a magnolia tree, and asked, "How much do I actually need to prune? How can I tell whether a branch or twig needs to be cut off or left alone?" Before you go crazy pruning your specimen, sit back for a moment with a relaxing drink and read the information below. These tips could prevent you from rushing off and damaging the tree in your current state of despair.

Pruning Magnolia Trees With Dead Branches: How Far Do You Go? 

You have dead limbs on your prized magnolia tree. You wonder:

  1. Is it safe to prune the dead limbs off?
  2. How do I know where to stop pruning?

We will get to the answers momentarily. First, though, assemble your pruning tools. Try to have the following on hand (you may not use all of them on this job, but they are handy tools to have, nevertheless):

In addition, have a sharp knife ready for this pruning project.

What and How to Prune

First of all, go ahead and prune off the branches, portions of branches, or twigs on your magnolia trees that are obviously dead. They can no longer be of any service to your tree and may actually invite pests and/or diseases. So #1 above is easily answered.

#2 is the tougher of the two questions to answer. First, let's elaborate on the issue, to make sure that all readers understand the nature of the question.

Consider the following scenario:

  1. Walking your landscape in early spring one day after a harsh winter, you see that your magnolia tree is in bad shape.
  2. After pruning off the branches that are obviously dead, you start to become discouraged. Your pessimism also causes you to become a bit trigger happy with your loppers.
  1. But you stop yourself from getting carried away with your pruning, because you say to yourself, "Just because one branch or twig is dead, that does not necessarily mean that the one right next to it is also dead."
  2. So the challenge becomes how to determine which branches or twigs are still alive and which are dead (in cases, that is, where the answer is not obvious).

How to Tell Dead Branches and Twigs From Lives Ones: Rule of Thumb 

A rule of thumb for tree care concerning this second question is: When you see green, stop pruning because when you find green, you have found life. But how do you determine where the green (under the bark) begins and the gray or brown leaves off? After all, this is not visible, because it is not on the surface. You need a way to peek into the inner workings of the tree.

Using a knife, cut into the bark of your magnolia tree here and there, in search of green; think of it as a spot check. In the process of checking for life in this way, you do not want to damage the tree by cutting into it excessively. The idea is to just scrape away a bit of the bark in select places, so that you can have a look "under the hood," so to speak.

You will need to make this determination wherever you have left off pruning the limbs that are obviously dead.

Once you find green, you will know to leave off pruning, because those branches or twigs are healthy. By contrast, if only brown or gray is present, you will know that the branch or twig is dead.