Why, When and How much to prune
Why – For future good health, prune a tree to establish good branch structure, good branch spacing, and one central leader. For safety, prune to insure that sight lines for bikers, motorists, or pedestrians are not blocked. Prune limbs to reduce conflicts with traffic signs, utilities, and to prevent other potential hazards. For aesthetics, a well maintained tree looks good and adds property value.
When – Prune when the tree is dormant, typically November through March although minor pruning can be done year round. Oaks should not be pruned from April 15 through July 1 to reduce the potential spread of Oak wilt disease.
How much to prune – Avoid removing more than 25% of the trees branches no matter what the trees’ size, age or species.
What to Do
Before pruning, take a step back and look at the tree, taking into consideration what you want to accomplish. Envision your tree after it is pruned, remember you can’t put it back on!!!!
Always have a purpose in mind before making a cut. This might be to eliminate competing leaders, crossing branches, broken or rubbing branches, or suckers.
What Not to Do
Avoid leaving too much or too little of the pruned branch. Leave approximately 1/16” of wood at the cut by the trunk. This will provide enough tissue for the plant to heal at the cut but not to much wood that could become subject to decay.
Never top your tree. Don’t make the mistake of cutting off the top of the tree’s canopy to reduce its size. Besides being unattractive topping leads to weak growth and decay.
How to Prune
Tools should be sharp so that they cut and don’t crush the limb. Loppers and hand pruners should be the bypass or scissors type. Saw blades should have triple edged teeth.
A hard hat, leather gloves and safety glasses are highly recommended and in some cases should be considered mandatory.
The following steps are recommended for all branches that cannot be supported by one hand while cutting with the other. Failing to follow these steps can result in torn bark which in turn can lead to decay.
Step 1) At least 12”-18” from the final cut make an undercut approximately 1/3 through the lower side of the branch.
Step 2) Outside of the first cut, saw from the top down and completely remove the branch.
Step 3) Make the final cut outside the branch bark ridge, continuing at a slight outward angle. It is not necessary or recommended to paint the wound.
By following the above advise you will maintain a tree that is healthy, does not pose safety concerns for pedestrians and motorists, and is aesthetically pleasing.