A Guide to Tree Pruning

If you still have Christmas lights draped around your trees, you might want to start uncoiling them because the prime time for tree pruning is fast approaching. The typical Minnesota winter doesn't provide much motivation for yard work, so I encourage you to instead find motivation in the results of tree pruning – healthy, beautiful, bountiful trees!

Why Prune?

So, what's the point of tree pruning? If you have to brave the frigid temperatures and tromp through piles of snow, it better be worth it, right? It most definitely is! There are a variety of reasons trees need pruning – removing damaged or diseased braches, reducing the height of the tree, removing dense branches that don't allow sunlight and air circulation, shaping or maintaining the shape of the tree for aesthetic purposes, promoting flower and fruit growth, and removing obstructing branches. As you can see, pruning is an essential step in helping trees thrive!

During the Winter?

Why does it need to be done in the winter? Well, because trees are dormant during the winter, removing branches won't hurt them, and sap flow is not as heavy, so trees won't bleed as much. And, since the leaves are gone and you can better see the structure of the tree, you can easily identify what needs to be removed. It also makes cleanup a lot easier, since without the leaves, you have less debris to take care of. Finally, if you have older, larger trees that require work by the pros, you eliminate the possibility of damage to your yard from trucks or large braches falling, when it is frozen.

What Do I Do?

If you've made the decision to bundle up and head out to the yard, read these tips before you get started! If you have young trees, it's best to get started now; by starting early, you avoid having to make larger wounds to the tree when it's bigger, and you can help guide where the growth goes.

When pruning, your goal should be to remove the undesirable branch, while protecting the stem and trunk wood of the tree. The branch collar, which is located at the base of the branch, separates the branches and stems from the trunk of the tree; when you make your cuts, be sure to leave the branch collar intact.

As you can see in the diagram above, the best technique is to start by making a small notch on the underside of the branch; this breaks the bark and prevents it from tearing. Next, further along up the branch, cut completely through the branch, leaving just a stub behind. Lastly, on the branch side of the branch collar, make a third cut parallel to the previous cut, removing as much as possible (but not the branch collar!). Make sure to never remove more than ¼ of the live foliage.

These steps should get you on your way to successfully pruning your tree, and enjoying your healthy, well-groomed trees this summer. For more in-depth information on pruning, see the University of Minnesota's extensive guide or check out the Arbor Day Foundation's animated/interactive resource.