Tree Pruning
Why Is Tree Pruning Important By Professional Tree Expert?
In the urban areas, pruning of trees is a tool for their care and regular maintenance. Pruning and training trees and shrubs when they are young will help ensure good growth and long-term structural stability. The purposes of pruning young trees are correction of the growth defects and stable structure of their crown. In adult trees, pruning is used to enhance their operational safety – mechanical and biological stability. Pruning has been called “one of the best, worst maintenance
practices” performed
on trees. The process creates wounds, which have a major impact on plant processes. Improper cutting on a tree causes severe damage or even death. To prune properly, it is important to understand both the proper techniques and how the tree responds to pruning. Regardless of who is pruning, doing it right and doing it safely are important. This dangerous work requires expertise and training to prevent injury or unnecessary damage. Never let the situation exceed your skills! If you are uncertain about how to prune large trees, contact a professional tree expert to assist you.
Reasons for Pruning
Let’s begin with why we want to prune a tree in the first place. The most common reasons typically include aesthetics, structure, and reducing risk. Typically, people prune to improve the appearance of the tree by reducing the length of fast-growing stems or unwanted growth. However, too many times trees are pruned only to maintain a desired shape or size to fit a location in the landscape. This can be
the result of poor placement
or because the wrong tree was selected for the intended space. Sometimes pruning is necessary to remove dead or dying branches or those affected by insect damage or disease. This helps defend against the spread of the pest and prevent further damage. Also, pruning can increase the vitality of the plant to improve flowering and fruit production. The most important reason to prune is to reduce
the risk of tree failure
especially in the crown. This includes removing defective branches on a declining tree or branches damaged by a storm. Risk reduction and the improvement of tree stability are important pruning objectives. Begin this type of pruning when the tree is young and newly established. A larger, mature tree often requires professional arborists to remedy structural concerns and other issues affecting
clearance, risk, and safety.
Good pruning actually starts with planning—and choosing the right tree. The goal is to minimize inputs and maximize
the benefits trees provide, and this starts with proper tree selection and placement. Planning for the right tree in the right place reduces the need for continual pruning. Know the mature size of the tree for its location; determine if it will fit the intended space as it matures and grows before planting.
Reduced-maintenance
plantings also include smart selection of good quality plant material. Choosing trees is much like purchasing any product: you get what you pay for, and the tree you select can determine long-term maintenance. Start out right by purchasing from a reputable source, such as a dedicated nursery or
garden center. Then, recognize
how to choose trees that are healthy and vital with good branch structure and spacing. Do not buy and plant trees with many narrow branch angles, excessive branching, or other structural issues. Also, spacing trees properly will reduce complications later as they grow into maturity. Overcrowding trees and plants can cause maintenance headaches and unnecessary costs with excessive pruning and even removal of plants to accommodate growth. Pay attention to the projected mature height and width of the tree during the selection process. Right tree, right place can have a major impact on pruning and other maintenance requirements.
Basic Pruning Principles That Only You As A Professional Knows
Any agricultural practice—including pruning—should not damage or impair the health of the tree. Proper technique and timing are critical to long-term tree health. The most important principle to remember is that each cut has the potential to change the tree considerably. Pruning trees should not be a common practice used to force them into aesthetic constraints or spaces. However, in distinctive circumstances such as espalier, proprietaries or pol larding, specialized pruning practices would be
necessary. There are times
when trees and other features in the landscape conflict with each other as part of the maturation process. Occasional pruning may be required during the life of the tree to remove branches interfering with buildings or with pedestrian or vehicular traffic. So, plan for a location that allows the tree to expand into its natural shape with limited conflicts, reducing the need for continual pruning
Another key principle is the pruning
dose—or amount of green tissue mass removed during any one pruning episode. Pruning amounts will depend upon previous pruning cycles and pruning objectives. How long has it been since the last pruning episode? What do you want to accomplish with this pruning activity? These questions will determine amount of pruning necessary. If extensive pruning
is needed, consider phasing
in the pruning process over a period of several months or years. Removing dead, damaged, or dying tree parts doesn’t figure into the mass when calculating pruning dose. However, severe pruning, especially during times of stress such as drought conditions, can have severe consequences on tree health. There are some things you should never do as a tree service professional. Topping is one of them. Topping is a form of poor pruning that can ruin the tree’s shape and health with excessive
canopy removal and poor cut
. Topping is the indiscriminate removal of branches between inter nodes and not where branches meet, leaving stubs and wounds which cannot heal properly. This provides the opportunity for disease and decay, creating serious problems for the tree. The tree responds to topping by producing many sprouts that are poorly attached and prone to damage from wind, ice, and snow. The dormant buds on the stems, which have flushed, are only connected to the xylem and do not overlap or commingle with the main supporting stem. This is a poor attachment that grows quickly and will become a safety
concern. Because of this weak
attachment, the branches are likely to fail more easily and pose a higher risk of injury or damage around the tree. The topping process typically involves large branches that are removed, leaving massive wounds that cannot compartmentalize and lead to decay as a result. Pruned branches should be removed back to a point of origin. If a branch must be removed or reduced, it should be cut back to
a lateral that is large enough
to assume the terminal role. The best practice for this is to cut back to a lateral that is at least 1/3 the diameter of the limb being removed. However, if large cuts are involved, the tree may not be able to seal over and compartmentalize the wounds. When severe pruning is required and excessive, sometimes the best solution is to remove the tree and replace it with a species that is more appropriate for the site. Topped trees present a serious risk to the tree owner and those around the tree. Never use any tree care company that advertises topping.
Trees Response To Pruning
Trees are complex organisms that respond to pruning in development, root growth, and quantity of leaf tissue produced. In simplest terms, pruning creates potentially serious wounds in the tree. However, pruned properly, a healthy tree can completely recover from the wounds caused by pruning cuts. Trees wounded in any way have a natural defense mechanism, which allows them to recover. This process is called COD IT (Compartmentalization of Decay in Trees), which is walling-off or sealing
affected areas to prevent decay
from spreading from the point of the wound into the tree. COD IT allows the tree to survive from wounds such as pruning. However, it is important to minimize wounding to facilitate faster recovery. The ability to seal off wounds is largely dependent on the age, health, and species of tree. The healthier the tree, the better it recovers from injuries. Younger trees and those not suffering from stress can recover more rapidly than those subject to stress, pests, or other problems. Some species of trees are just more resourceful in their recovery process and recover more effectively.
It is important to make proper
cuts that allow callus growth to begin to close the wounded area. Each pruning cut requires valuable resources from the tree for healing. The larger the cut, the more time and resources are required to recover. Small cuts always are better than larger pruning cuts. The smaller cuts minimize the amount of tissue exposed to pathogens and expedite the healing time more efficiently. Research suggests that in trees that seal poorly (such as maples, birches, poplars, and crab apples) pruning cuts should
be no larger than 2 inches
in diameter. On trees that are better compartmentalizes or better at sealing off wounded areas (most oaks, elms, lindens, and hornbeam), 4 inches in diameter should be the maximum-size branch removed. Limiting the size of the wound better enables the tree to seal the wound. If larger branches need to be removed, consider a progressive pruning cycle. This makes a great case for structural pruning of trees while they are still young and relatively smaller (more on this later). Wound size and efficiency of the tree’s ability to seal the wound are critical for long-term health. Pruning can strengthen a stem by encouraging growth or stimulating additional branching, but the affects
depend upon both the amount
of cutting and timing of the practice. Overall, the practice of pruning not only affects the canopy, but can also affect the roots. Fewer green leaves to produce food can also mean fewer roots and less food storage capability. Excessive removal of large branches and removal of large masses of leaves reduces the tree’s ability to create food and energy. Also, this excessive pruning creates serious root
issues and can limit root grow
the dramatically. Food, water, hormones, and other petrochemicals are constantly moving in the pathways between the roots and shoots of the tree. Excessive pruning will cause roots to recede and decline, leaving the tree less able to take up needed water and transport important nutrients.
Only You As A Professional Knows How To Make A Better Pruning Cut!
The practices used for pruning depend on size of the branch to be cut; whether or not the branch is safely and easily supported by one hand while cutting; and if a simple, single cut can be made with hand pruners, toppers, or a hand saw. Only a professional knows this! If the branch is too large to support with one hand, you’ll need to use a specialized cutting technique and, most likely, a hand saw
Before making any cut
remember to identify the branch components to insure proper alignment of the pruners, toppers, or saw during the cut. When removing any branch or limb, always make the cut just outside the branch bark ridge and the collar when it is present. Branches that are too large to be supported by hand should be removed using the ternary method to avoid tearing or splitting the bark and damaging the
branch protection zone
(It was formerly called the “double-cut,” which is a misnomer, because it actually takes three cuts to finish the process, rather than two as the name implies.) Arborists now refer to this pruning cut as the “three-cut method” or ternary method. In the ternary method, the first cut, called the undercut, begins on the bottom of the branch anywhere from 6 to 12 inches away from the branch union. The second
cut, called the top cut
is made above or just outside of the undercut; proceed with the saw from the top of the branch moving downward. This is the pruning cut that allows the branch to be cut away completely. As the saw moves through the wood the branch will naturally fall as gravity takes over. This “top cut” will soon meet the plane of the previous undercut, stopping it and preventing the bark from ripping. After
both cuts have been made
the branch should easily fall and be removed. However, the job is not finished! Make the third and final cut just outside the branch bark ridge and the outer portion of the branch collar on the bottom side of the attachment. Now that a proper cut has been made, let the sealing begin! Determining the
two points on the branch
to align the cut can be challenging at times, especially when the branch collar may not be readily visible. In this situation, identify the branch bark ridge, which is always present, and cut at an angle, typically at a right angle with the top of the branch to be removed, which minimizes the wound size, revealing the least amount of exposed tissue. The smaller the wound, the faster and more efficiently
the tree seals the
cut. If removing a dead branch, sever the branch just outside the area where the wound wood has formed. Take care not to damage any of the newly formed callus tissue. This will eventually seal off the exposed tissue from the cut. Poor pruning cuts, leaving rips, stubs, or flush cuts, create many issues detrimental to recovery. Pruning without damaging the branch collar and branch bark ridge encourages the formation of a callus that seals the wound and protects the tree. Never “flush-cut” a
branch, because that removes
the tree’s ability to recover quickly and effectively. Also, never leave the stub behind outside the branch collar area. This leaves a woody material with no support from leaf tissue; it will soon decay and provide a conduit for disease to spread into the remaining branch or stem. It continues to be
accepted that tree wound
dressings are not needed on pruning cuts and provide no benefit to the tree. In fact, many dressings inhibit closure of the wound and slow the sealing process. Many of these are petroleum-based products, which can kill the cells responsible for callus development and wound closure.
Conclusion
Pruning is often a necessary activity, yet it can be devastating if done incorrectly. The best advice for any tree maintenance, including pruning, is to never let the situation exceed your skills. If you don’t know what you are doing when it comes to tree maintenance activities, leave it alone. There are many resources available to the tree owner to assist with plant health care decisions. Be sure assistance comes from tree care professionals with recognized credentials and references. It saves a lot of stress
