There are misconceptions about how to prune a tree. Here are seven things you need to know before you begin.

1. Always have a reason for each cut you make on a tree. A beautiful day and hearing you need to prune now are not the right reasons. The main reasons we trim our trees are to support strong tree structure, encourage fruit production, prevent damage, provide clearance to avoid conflicts, shape the tree for aesthetic reasons and repair the tree from previous damage.

2. Chose the right time of the year. There are good times of the year to prune. Pruning at other times can lead to tree distress and disease. Prune during late winter and early spring, just as trees are coming out of dormancy and will be actively growing soon. For fruit trees, wait until they have flowered before pruning to encourage production and direct growth.

3. Use good hand tools, including a bypass hand pruner and scabbard, 8” folding hand saw, long reach pruner and orchard ladder (step ladders on uneven ground can be dangerous). As fun as they may seem, never use a chainsaw unless operating from the ground below shoulder height. Always wear PPE including safety chaps. Remember to sterilize tools with alcohol or Lysol spray when moving between trees.

Hand Pruner and Bypass Pruning Shears

4. Know your tree type. To figure out your tree type and its particular needs, try some plant identification apps, read the Arbor Day Foundation brochure “what tree is that.” or take photos of the tree and ask an expert. Pictures should include the overall tree form, leaves, bark, flowers or fruit. The most common trees in the Albuquerque landscapes are honey locust, Modesto ash, Siberian elm, London planetree, desert willow, Austrian pine, ashes, ornamental pear, Afghan pine, purple leaf plum, cottonwoods, golden raintree, Chinese pistache, pinon pine, redbuds, crabapples, Navajo willow, Texas red oak and mimosa.  

5. Check out your tree’s health. How much water does it need and if/when does it need to be pruned? Highly-stressed trees should not have living branches pruned or removed. A healthy tree’s overall vigor and branch growth from previous years should be around 3”- 4” of growth per year between a bud scar and a new terminal bud. Access the density of the canopy all around and under the tree. For healthy conifers look for four years’ worth of needles on a branch. Less than two years on a branch is considered stressed.

6. Know the three types of pruning cuts: heading, removal and reduction. Avoid heading unless attempting to correct damage. Removal describes cutting branches all the way back to the main trunk. Remove 1” caliper branches and avoid cutting anything bigger than 3”. Some trees, like our local cottonwood, may not be able to heal large wounds. Reduction cut is the ideal cut. It is used to redirect and subordinate growth. Reduction cutting allows the tree to heal properly. Prune back to a branch that is at least 1/3 the size of the branch removed in order to avoid excess sprouting and allow the remaining branch to assert dominance.

7. Know where and how to make the cut. Refer to the diagrams to properly identify the branch collar, which contains the Branch Protection Zone (BPZ) that has specialized tissues which resist the passage of decay organisms into the trunk. Cut about 1/2” outside the branch collar. This allows for proper wound healing. Use the following three-step method when making a cut: First, make a partial upward cut several inches out from the final cut. Next, make a full downward cut a half inch farther out to take the weight off. Lastly, make the final cut without nicking the branch collar.

By reviewing and understanding these seven tree pruning concepts you are well on your way to properly pruning your trees. Remember, tree pruning is only needed every few years. The proper watering of your trees needs to happen monthly. Check out the other tree health articles below to keep yours in tip-top shape.

Learn more about tree health here:

The Balancing Act of Watering Trees In Winter

Help, my trees need pruning!

The Basics of Fruit Tree Pruning

Author: Amos Arber, Xeriscape Rebate Inspector with the Water Resources Conservation Department for the Water Authority. Have a question about the article? AskAnExpert@abcwua.org