Mature trees

The pruning of large shade trees by the homeowner should be limited to the branches that can be reached from the ground. If large limbs need to be removed, enlist the professional services of a certified arborist with the proper skills, equipment and insurance. Observe caution when pruning around power or utility lines. Employ a trained arborist for pruning near hazardous areas.

Figure 13. Diagram of radial spacing

Selective Cutting Diagram
Figure 14. Anatomy of a tree

It is not necessary or desirable to cut back the canopy of a tree when transplanting. A substantial portion of a tree's root system is left in the production field when harvested as ball and burlap or bare-root. It may appear logical to prune the tree to balance things out. Research has proven that trees cut back at planting do no better and sometimes do worse than trees that are not cut back. Cutting back a dormant tree can actually delay bud break in spring and slow the tree's initial growth.

Improper pruning can cause irreparable damage. Pruning cuts should be made for a reason and with the knowledge of how the tree will respond to the cut. Certified arborists use pruning techniques based on the condition and site of the tree, and the desired goal of the job. Pruning should focus on maintaining tree structure, form, health and appearance. Common methods to prune large trees are crown thinning, crown cleaning, crown or height crown reduction and crown raising. Discuss with the arborist the best and most desired method of pruning before the work is done

Regardless of the method chosen, branches should be cut back to the origin or to a lateral branch that is at least one-third of the diameter of the parent branch. The final cut should be just outside the branch collar. Leaving stubs or flush-cutting may lead to decay and slow closure of the pruning wound.

Each cut should leave a smooth surface with no jagged edges or torn bark. Large or heavy limbs, 1 1/2 inches or greater, should be removed using the three-cut method. The first cut is an undercut on the targeted branch about 10-12 inches (1 to 2 feet on extremely

Terms associated with pruning large shade trees:

Crown cleaning:

Selective removal of dead, dying, diseased or weak branches or water sprouts.

Crown thinning:

Selective removal of healthy, live branches to increase light penetration or movement and reduce weight.

Cleaning typically done at the same time.

One-half of the foliage must be left on the lower one-third of the tree so these branches promote growth and limb strength.

Crown raising:

Removal of lower branches for clearance. Some horticulturists refer to this as limbing-up the canopy.

Crown reduction: Removal of live or dead branches to reduce the height or spread of the tree.

Cutting branches to larger laterals, never removing more than one-third of a tree's crown.

Cutting branches headed into a building or utility area.

Second cut

Branch bark ridge

Second cut

Branch Collar Pruning

Branch collar

Branch collar

Figure 15. Three-cut method with branch collar large branches) from the trunk. This cut prevents the branch from tearing bark farther down on the tree. The second cut is a top cut slightly farther out than the undercut (3-4 inches past the undercut), which allows the limb to drop without the weight of the limb causing damage to the tree trunk. The third and final cut removes the stub just outside of the branch collar. This cut should be smooth with no tears or jagged edges.

A common practice called "topping" is a severe problem in Tennessee. Topping is used to reduce the height of trees around homes and utility lines. Topping is not the same pruning method as crown or height reduction. Crown reduction does not leave stubs like

Pruning Trees Crown Thinning

A negleteà sfraàe tree lije work of a poorly cfaosen "tree expert"

T^e work of a Competent arborist

Figure 16. Topped trees

A negleteà sfraàe tree lije work of a poorly cfaosen "tree expert"

T^e work of a Competent arborist

Figure 16. Topped trees topping. There is never a good reason to top a tree. Topping removes the tree's main leader and branches, resulting in stubs. After topping, the new growth is disfigured, with watersprouts and weak limbs that form a dense canopy where very little air can penetrate. Insects and disease organisms thrive in this environment. The initial large wounds never heal properly and the subsequent growth is very weak. New limbs that are generated will break out easier than the branches that were removed. Topping drastically shortens the life of a tree. Topped trees are an eyesore in the landscape and continue to be an eyesore as trees slowly decline.

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Responses

  • Jeanette
    What trees that respond to selective cutting?
    6 years ago
  • timba gaukrogers
    How to reduce a tree height?
    6 years ago
  • aida
    How to cut trees diagram?
    5 years ago

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