Tree dieback is a complex syndrome and slow developing. Dieback is essentially a process in which trees lose leaves and limbs. This usually occurs as a result of severe stress to the tree’s bark or root system, but could be a result of a declining life cycle.

It’s important to note that there is a significant balance between a tree’s root system and the number of leaves and limbs it can support.  For example, if a tree loses part of its root system, possibly due to disease or lawn equipment damage, the tree will forfeit a portion of its leaves. Dieback doesn’t happen overnight, though. It’s a slow process, with larger trees taking much longer time for signs of stress to emerge.  However, a large tree root system is very sensitive to damage, whereas a small tree will adapt quickly and is much more resilient to damage.  So, what can be done to prevent dieback in trees?

First and foremost, trees, like all living things, have a natural life cycle.  Regardless of how you care for your trees, dieback will occur. The most important management measure in extending the life of a tree is to protect the root system and bark.

With each passing year, a tree grows new bark in the rejuvenation process.  The bark replacement process inevitably becomes more difficult as the tree gets older and in turn the tree is more and more susceptible to dieback. If the bark becomes damaged, especially later in the tree’s life cycle, then fungi and insects have a much greater chance to cause serious harm. Treating bark damage with a wound dressing to prevent decay is the recommended procedure.

Lichens come in many forms and are commonly blamed for the decline and death of trees and shrubs, however they do not cause harm. Credit. Sydney Park Brown and Joseph Sewards, UF/IFAS.

A common misconception is that epiphytes, such as lichens and Spanish moss, are tree diseases. Epiphytes are known as “air plants” and thrive in the Panhandle. They survive on moisture and nutrients in the atmosphere and are harmless to trees. However, a tree that becomes inundated with epiphytes may be an indicator of excessive soil moisture, which may lead to root rot.

Lawn weed killers can have detrimental effects to trees, even if the application seems to be from a safe distance.  When using a weed killer near a tree’s root system, confirm on the label that the product is designed to kill green growth only. It can’t be overstated that excessively fertilizing an old tree will greatly accelerate the decline of the tree. Some may think this will stimulate a tree and extend its life, but instead it will do the opposite. Young trees can tolerate fertilizer applications, as they need crown growth. Older trees will simply become top heavy, and structural damage will likely occur.

Don’t forget, trees need space too.  A mature tree forced to occupy a small space will simply not adapt. Be sure to have adequate spacing when planting younger trees and shrubs in the vicinity of older trees. Also, keep your trees pruned away from touching structures and utilities.

Tree dieback is a complex issue to manage. By following these measures, you can help extend the life of your trees and continue to have a picturesque landscape.

For more information on tree dieback, contact your local county extension office.

Please visit Florida Friendly Landscaping, http://fyn.ifas.ufl.edu/, for more information on maintaining your landscape.

For more general  information on lichens, please see UF/IFAS EDIS document “Spanish Moss, Ball Moss and Lichens-Harmless Epiphytes” by Joe Sewards and Dr. Sydney Park Brown: https://edis.ifas.ufl.edu/pdffiles/EP/EP48500.pdf

UF/IFAS Extension is an Equal Opportunity Institution.

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