WHY TOPPING HURTS TREES

    Topping is perhaps the most harmful tree pruning practice known.
    Yet, despite more than 25 years of literature and seminars explaining
    its harmful effects, topping remains a common practice. This page
    explains why topping is not an acceptable pruning technique and
    offers better alternatives.
    What is Topping?

    Topping is the indiscriminate cutting of tree branches to stubs or lateral
    branches that are not large enough to assume the terminal role. Other
    names for topping include “heading,” “tipping,” “hat-racking,” and “rounding
    over.”
    The most common reason given for topping is to reduce the size of a tree.
    Home owners often feel that their trees have become too large for their
    property. People fear that tall trees may pose a hazard. Topping, however,
    is not a viable method of height reduction and certainly does not reduce the
    hazard. In fact, topping will make a tree more hazardous in the long term.
    Topping Stresses Trees
    Topping often removes 50 to 100 percent of the leaf-bearing crown of a tree.
    Because leaves are the food factories of a tree, removing them can
    temporarily starve a tree. The severity of the pruning triggers a sort of
    survival mechanism. The tree activates latent buds, forcing the rapid growth
    of multiple shoots below each cut. The tree needs to put out a new crop of
    leaves as soon as possible. If a tree does not have the stored energy
    reserves to do so, it will be seriously weakened and may die.
    A stressed tree is more vulnerable to insect and disease infestations.
    Large, open pruning wounds expose the sapwood and heartwood to
    attacks. The tree may lack sufficient energy to chemically defend the
    wounds against invasion, and some insects are actually attracted to the
    chemical signals trees release.
    Topping Causes Decay
    The preferred location to make a pruning cut is just beyond the branch collar
    at the branch’s point of attachment. The tree is biologically equipped to
    close such a wound, provided the tree is healthy enough and the wound is
    not too large. Cuts made along a limb between lateral branches create
    stubs with wounds that the tree may not be able to close. The exposed
    wood tissues begin to decay. Normally, a tree will “wall off,” or
    compartmentalize, the decaying tissues, but few trees can defend the
    multiple severe wounds caused by topping. The decay organisms are given
    a free path to move down through the branches.
    Topping Can Lead to Sunburn
    Branches within a tree’s crown produce thousands of leaves to absorb
    sunlight. When the leaves are removed, the remaining branches and trunk
    are suddenly exposed to high levels of light and heat. The result may be
    sunburn of the tissues beneath the bark, which can lead to cankers, bark
    splitting, and death of some branches.
    Topping Creates Hazards
    The survival mechanism that causes a tree to produce multiple shoots
    below each topping cut comes at great expense to the tree. These shoots
    develop from buds near the surface of the old branches. Unlike normal
    branches that develop in a socket of overlapping wood tissues, these new
    shoots are anchored only in the outermost layers of the parent branches.
    The new shoots grow quickly, as much as 20 feet in one year, in some
    species. Unfortunately, the shoots are prone to breaking, especially during
    windy conditions. The irony is that while the goal was to reduce the tree’s
    height to make it safer, it has been made more hazardous than before.
    Topping Makes Trees Ugly
    The natural branching structure of a tree is a biological wonder. Trees form
    a variety of shapes and growth habits, all with the same goal of presenting
    their leaves to the sun. Topping removes the ends of the branches, often
    leaving ugly stubs. Topping destroys the natural form of a tree.
    Without leaves (up to 6 months of the year in temperate climates), a topped
    tree appears disfigured and mutilated. With leaves, it is a dense ball of
    foliage, lacking its simple grace. A tree that has been topped can never
    fully regain its natural form.
    Topping Is Expensive
    The cost of topping a tree is not limited to what the perpetrator is paid. If the
    tree survives, it will require pruning again within a few years. It will either
    need to be reduced again or storm damage will have to be cleaned up. If the
    tree dies, it will have to be removed.
    Topping is a high-maintenance pruning practice, with some hidden costs.
    One is the reduction in property value. Healthy, well-maintained trees can
    add 10 to 20 percent to the value of a property. Disfigured, topped trees are
    considered an impending expense.
    Another possible cost of topped trees is potential liability. Topped trees are
    prone to breaking and can be hazardous. Because topping is considered
    an unacceptable pruning practice, any damage caused by branch failure of
    a topped tree may lead to a finding of negligence in a court of law.
    Alternatives to Topping
    Sometimes a tree must be reduced in height or spread. Providing clearance
    for utility lines is an example. There are recommended techniques for doing
    so. If practical, branches should be removed back to their point of origin. If
    a branch must be shortened, it should be cut back to a lateral that is large
    enough to assume the terminal role. A rule of thumb is to cut back to a
    lateral that is at least one-third the diameter of the limb being removed.
    This method of branch reduction helps to preserve the natural form of the
    tree. However, if large cuts are involved, the tree may not be able to close
    over and compartmentalize the wounds. Sometimes the best solution is to
    remove the tree and replace it with a species that is more appropriate for
    the site.
    Hiring an Arborist
    Pruning large trees can be dangerous. If pruning involves working above the
    ground or using power equipment, it is best to hire a professional arborist.
    Tree Works can determine the type of pruning that is necessary to improve
    the health, appearance, and safety of your trees. We can provide the
    services of a trained crew, with all of the required safety equipment and
    liability insurance.