Windstorm Damage of May 20, 2001
Disease Makes Trees More Vulnerable to High Winds

Example 8: Arizona Ash in Residential Yard

As with other trees, crotch injury in this species can be repaired (prior to a catastrophic event such as this; this limb cannot be reattached) by thoroughly cleaning the crevice, sealing the crotch to prevent fresh invasions of fungi and other organisms, and taking advantage of the tree's natural ability to repair itself. Repair does not occur over night, and care must be taken to reduce the stress on the crotch by surgically removing a considerable portion of the secondary growth present on the most vulnerable limb.

Bugsinthenews ... Trees in Central Texas




The Arizona Ash (Fraxinus velutina), which is also known as the Velvet Ash, is another fast growing tree favored by builders throughout central Texas. Unfortunately, it is not well suited to this climate or to the insects that abound here. As the tree matures, it often becomes unbalanced through poorly planned pruning of its branches. When a major branch projects off to the side and becomes weighed down with foliage, crotch injury is the common result, as in this tree. The crotch of this major limb has been split for several years, and the crevice has grown wider and deeper over that time. This windstorm delivered sufficient force to finish the job.

The wound caused by the windstorm must now be thoroughly cleansed of the detritus that had collected in the crotch, and treated with a fungicide to prevent heart rot in this tree. The rough edges of the damaged portion in the lower extremity of the wound should then be smoothed out, after which the entire wound should be thoroughly coated with a tough sealant to prevent invasion by pathogens and to encourage the cambium to encroach upon the wound and eventually cover it with scar tissue. The remaining limbs of this specimen should then be evaluated with a view towards achieving a balance that will avoid similar injury elsewhere in its branches in subsequent windstorms.