Landscape Architect Articles

LCN Tree Care November, 200411-01-04 | News

Painless Fall Trimming and Pruning

By Leslie McGuire, regional editor

After topping, the tree will never go back to its original form and will suffer sun damage and loss of nutrients.

Part of winterizing is getting your trees ready for the windstorms that inevitably come in the fall. Think hurricanes, snowstorms, blizzards and tornadoes.

Pruning for Wind Resistance

The most wind-resistant form for a tree is one with a central leader and a well-spaced framework of branches around and up and down the trunk. Most trees are grown in this form when they are young. Lower branches should be pruned to one-third the trees height. There should be no narrow forks or branches leaving the trunk at an acute angle since these branches are likely to split under stress. Crotches from 45 to 90 degrees are less likely to split than narrow V-crotches of less than 40 degrees.

A wind resistant tree is the result of regular care since its early life. Young trees should be encouraged to form a strong leader with well-spaced laterals (branches that go out to the side). Faced with the threat of a storm, the order of pruning is always the same.

To Top or Not To Top And Other Negative Pruning Techniques

As you may have gathered, there is no question in the minds of landscapers and arborists that topping is bad. It leaves the tree open to disease and insect pests. The tree’s natural reserves of nutrients are cut down. The shoots it grows to replenish its nutrients are weak and will likely suffer from wind damage. The bark of the tree will be damaged by sun and that will cause the formation of cankers, splitting and dead branches.

Sun damage results from poor pruning techniques such as topping.

In addition to topping, there are other very damaging pruning methods such as lion tailing, flush cutting and stub cutting.

Lion tailing is a pruning tactic that cuts off the branches attached to the larger limbs leaving only a tuft of leaves at the end of the limb. The heaviest part of the limb is located at the tip and that makes the limb vulnerable to wind damage. Flush cutting is a technique that involves cutting the limb off flush with the trunk. Stub cutting involves cutting the branch off too far from the trunk and is just as harmful as flush cutting. Whether they are long or short, the dead stubs are an invitation to disease and insects.

It’s important to note that painting the wound with pruning paint is unnecessary. If the tree is healthy and the pruning was done correctly, the tree has the ability to heal itself. Just remember, the point of pruning a tree is to make it more healthy, not to damage it, So, now that you know what to avoid, you can be confident that all the trees you prune will be better off and have long and happy lives.

Preparing For a Storm

Pruning without leaving a stub leaves the tree vulnerable to attack by insects and disease.

Cut out dead, diseased and damaged wood.
Take out watersprouts
Cut out crossing branches that clutter the center of the tree.
Select a well-spaced framework of branches and cut all others out completely.
Shorten branches to give a balanced head.

Heading back (cutting branches severely to a bare stump) should be avoided unless absolutely necessary. Not only does this risk sunburn for the trunk areas suddenly exposed to the light, it also means that a tuft of twigs will grow from each stump that will have to be thinned later.