Urban Environmental Department

Topping - A major threat to trees

Humans can threaten a tree's health at three levels. The roots: soil compaction, construction activities, and pollution (oil, herbicides, and toxic chemicals) can injure or kill roots, and weaken or kill the tree. The trunk: damage to the bark wounds the tree, and some of the energy needed for maintenance and growth of the tree's existing root and branch system is redirected to healing the wound instead. The crown: improper pruning and air pollution can result in a decline in food production in the leaves, and the entire tree suffers.

The most obvious way that trees are injured is by topping. Tree topping is the drastic removal of large branches that are cut back to stubs. Topping is an unacceptable practice, although many people are unaware of its detrimental effects. As a result, the homeowner may spend hundreds of dollars to perform this senseless act, often with the best of intentions. We'd like to share with you information about the consequences of topping and about the better alternatives that are available.

1. Starvation: Good pruning practices rarely remove more than 1/4 to 1/3 of the crown, which in turn does not seriously interfere with the ability of a tree's leafy crown to manufacture food. Topping removes so much of the crown that it upsets an older tree's well-developed crown-to-root ratio and temporarily cuts off its food-making ability.
2. Shock: A tree's crown is like an umbrella that shields much of the tree from the direct sun. By suddenly removing this protection, the remaining bark tissue is so exposed that sun scalding may result.
3. Insects and Disease: The large stubs of a topped tree have a difficult time forming callous. The stubs are highly vulnerable to insect invasion and the spores of decay fungi. If decay is already present in the limb, opening the limb will speed the spread of the disease.
4. Weak Limbs: At best, the wood of a new limb that sprouts after a larger limb is cut is more weakly attached than a limb that develops normally. If rot exists or develops at the severed end of the limb, the weight of the sprout makes a bad situation even worse. These limbs are much more likely to break and fall during a storm.
5. Rapid New Growth: The goal of topping is usually to control the height and spread of a tree. Actually, it has just the opposite effect. The resulting sprouts (often called water sprouts) are far more numerous than normal new growth and they elongate so rapidly that the tree returns to its original height in a very short time - and with a far denser crown.
6. Tree Death: Some older trees are more tolerant to topping than others. Trees that do not sprout readily after severe pruning have reduced foliage, therefore less food is manufactured and most of the time this leads to the direct death of the tree.
7. Ugliness: A topped tree is a disfigured tree. Even with its regrowth it never regains the grace and character of its species. The landscape and the community are robbed of a valuable asset.
8. Cost: To a worker with a saw, topping a tree is much easier than applying the skill and judgment of good pruning. Topping may cost less in the short run. However, the true costs of topping are hidden. These include: reduced property value, the expense of removal and replacement if the tree dies, the risk of damage from the weakened branches and increased future maintenance.

Also see the City's Tree Management Ordinance.

If you have any questions, please contact city horticulturist Cynthia Holloway at 895-8059.

Welcome!
from Cynthia Holloway, Director

On behalf of all the Murfreesboro Urban Environ-mental Department staff, I'd like to welcome you to ourweb page.

Our department is involved in all aspects of managing the city's urban forests and is committed to helping our citizens with all types of arboricultural-related issues. Murfreesboro's trees are a big part of what makes Murfreesboro the great city that it is and one of our department's main goals is to provide our citizens with information on how to protect, maintain and expand our valuable urban forest. It is also vitally important that we continue to educate our citizens about the importance of trees, and that we form partnerships with citizen groups, businesses, and others in order to promote and maintain public involvement in the long-term management of them. We need your help and support, and by working together, we can preserve and enhance the legacy of Murfreesboro's urban forests through wise stewardship and far-sighted leadership.

We hope that you will contact our department at any time should you have any questions or concerns about our services. We also welcome any suggestions or comments you may have regarding this site and how we may improve upon it.