Taking Care of your Trees: Winter Pruning

Proactive tree pruning management is necessary for health, beauty and longevity of your tree.  Late winter through early spring is considered the best time of year for pruning trees.  Outside of unseasonable warming trends, trees go dormant during the winter months and generally do not start sap flow until early spring. 

The reasons to take advantage of pruning deciduous trees during this time of year include:

  1. Lack of leaves allow the pruner to see the whole architecture of the tree and to select the most beneficial cuts
  2. Winter pruning minimizes wound exposure to insect and disease
  3. Winter pruning minimizes the time to begin “healing” in spring.
  4. Pruning allows for outdoor activities during the cabin fever days of winter

The best long term tree management decision occurs at planting.  Choosing the right tree and planting it in the right place allows the tree to grow to its natural size and form where it may need little or no pruning after it becomes established. Yearly pruning during the first few years after planting will often help the tree to become established and to develop a structure that is both strong and aesthetically pleasing for the life of the tree. 

For established trees, the best way to plan your pruning attack is to study the natural architecture of your tree from a distance of 50 to 100 feet. First pruning cuts should be directed towards obvious unwanted materials such as dead or dying branches, any cross branches or ones growing towards the tree center and any sprouts or suckers growing at the base of the trunk.  After removing the unwanted materials, step back away from the tree for the second round of observations prior to more critical pruning cuts.

Remove branches or cut them back if they have the potential to be hazards in the future.  For instance, large limbs growing towards roofs or power lines and lower branches that interfere with traffic or sidewalks.  If your tree has more than one central leader (two or more branches competing for the top dominance), cut out all but the strongest so that the tree will regain its normal shape and development.  In some cases, single side branches can develop more rapidly than surrounding branches and need to be cut back to slow growth and allow others to catch up.  As a general rule, it is never a good practice to prune more than 20% of growth in any given year.

Pruning can involve use of potentially dangerous tools: (pruning loppers, chainsaws, pole saws and ladders) so always remember safety first before starting any project.  When cutting large branches, it is best to use the three cut method (See Figure below).  Starting approximately 12 inches from the trunk, make the first cut ¼ through on the underside of the branch to be removed.  At the same location but on the upper side, the second cut can then be accomplished to remove the weight of the branch.  The previous undercut will eliminate bark pealing back to the trunk.   The last cut is then made at the branch collar perpendicular to the branch growth.  This last cut minimizes the diameter of the cut and allows the most efficient wound for healing.  When using loppers on smaller branches, the collar may not be as evident but similar cut principles should be applied to minimize damaging cuts. 

It has often been stated that it is easier to practice pruning techniques on a neighbor’s tree, but if these pruning strategies are implemented, it will be easier to start closer to home.  With any pruning strategies, remember to be safe first as limbs are not easily reattached (plant or human).

More information on Pruning and Care of Shade Trees (MU Guide 6866), First Aid for Storm damaged trees (MU Guide 6867), Basic Chainsaw Safety and Use ( MU Guide 1959) are available at your local University of Missouri Extension office or online: extension.missouri.edu  

Source: Todd Lorenz, MU Extension Agronomy Specialist