What most people do not realize or understand it that every pruning cut you make on a plant causes some type of physiological response in the plant. Once you have a better understanding of this cause/effect relationship you can learn how and when to prune with more certainty of the results you will produce.
Pruning is both an art and a science! Mistakes can be made and also…mistakes can be avoided!
Fact 1: Make Fewer but Larger Cuts to Control Size
If you wish to maintain a tree or shrub at a certain size or shape make fewer but larger cuts. A few large branches removed will not stimulate multiple new bud breaks and will help limit the ultimate size of the plant.
Application: This fact is helpful if you wish to maintain the size of a tree within the confines of the space available for this tree or plant. Perhaps the tree has grown tired and is not pushing out much new growth annually. This method will generate new vigour and will ‘Kick” the plant back to life. This is also most useful when you wish to create more density in a tree or evergreen perhaps to make a barrier hedge more dense and vibrant.
Fact 2: Stimulate Growth with Multiple Smaller Cuts
If you wish to invigorate a tree or plant to produce a flush of new growth and multiple new bud breaks (multiple branching etc.), the key is to make many smaller “heading” cuts on multiple branches.
Application: Perhaps the tree has grown tired and is not pushing out much new growth annually. This method will generate new vigour and will ‘Kick” the plant back to life. This is also most useful when you wish to create more density in a tree or evergreen perhaps to make a barrier hedge more dense and vibrant.
Fact 3: Redirect Growth by Strategic Pruning
You can “Re-direct” tree or shrub growth where you want it by pruning on the opposite side from where you want the new growth and thus direct the response where you want it.
Application: This fact and technique is useful when you want to fill in an area of the plant which is not growing well. Also useful when you wish to reduce vertical growth and expand horizontal growth by “Heading Back” the leader or in some cases, multiple leaders.
Fact 4: Remove Competing Branches to Support Weaker Ones
A larger diameter branch will always outgrow and hence, over-compete with a smaller branch. When you wish to insure the direction and success of a smaller branch, simply remove the competing branch to provide opportunity for the weaker or smaller branch to take over.
Application: Often in younger trees becoming established on your property there will be a dominant branch with larger diameter where you do not want it, simply remove this and the desired branch will gain dominance.
Fact 5: Vertical Shoots Grow Faster but Are Less Fruitful
Vertical shoots will almost always grow with more vigor and dominance than more horizontal branching. Trees seek the light and vertical growth will do this faster than horizontal growth.
Application: This is especially important in fruit tree production as well layered horizontal branching will provide a better scaffold and support more and better quality fruit production. Vertical shoots will almost always remain vegetative and hence will grow less and lower quality fruit.
Fact 6: Reestablish a Lost Central Leader
If for some reason your tree has lost its central leader and you want to re-establish a new leader it is relatively easy. This may be due to mechanical damage from snow load, wildlife activity or some other cause, perhaps wind or ice-load.
Application: The method is to cut back the broken branch to about 2 inches above a new shoot or a good strong bud. Once the growth of the new shoot has begun before it becomes too lignified (hard), just tie in the new leader to the stump of the old one using masking tape. The new shoot will gain dominance in in a short time the masking tape will simply disintegrate.
Fact 7: Proper Cuts Ensure Faster Healing
The correct pruning technique will insure that any branch removal will completely heal over in time; however, the wrong kind of cut will insure that it won’t heal or at best, will be much slower. A new branch attaches to the parent branch with a small raised ridge called the “branch bark ridge” or “The Branch Collar” This critical area contains the mechanism that will create a new ring of callous material that will ultimately, close over the pruning cut and heal the tree with new bark. However, if you remove this while pruning the branch has lost this advantage.
Bonus Fact: Skip the Wound Dressing
So here is a freebie! Pruning cuts and wounds to trees will heal better if not treated with a wound dressing. The tree within its own amazing physiology has the natural ability to create a walled off layer under the surface that will allow the wound to heal on its own.
By adding a dressing you are certain to trap both moisture and pathogens under this coating and thus increase the probability of rot and decay.
Final Thoughts
Pruning is a powerful tool for shaping and maintaining your garden, but it requires knowledge and precision. By following these critical facts, you can ensure your trees and shrubs remain healthy, beautiful, and productive.
Cheers,
Eric Warren
The Gardeners Friend