Uncovering the Hidden Roots of Tree Health

Written by: Michael Peterson, ISA Certified Arborist WI-1293A

Posted: 2024 | Construction Protection | Root Collar Excavation | Spring | Tree and Shrub Care

As a Certified Arborist, I love diving into the stories of trees and their connection to your property. Recently, I had the opportunity to review two 100-year-old white oaks on the south side of
Pewaukee Lake whose tale unfolded in a fascinating way.

They exhibited large dead sections and some shriveled yellow leaves despite most of the canopy appearing healthy. I explored the base of each tree and made an unexpected discovery. Unlike the typical gradual transition from trunk to roots found in a forest setting, these displayed no slope in their roots, i.e., no “root flare.” Concerned, I suggested excavating to locate the “root flare.”
At a depth of 12-14 inches, we only barely uncovered a slope—very unusual.

In the following weeks, the client stumbled upon property photos from the 60s and 70s depicting a front yard with a significant downward slope. Revelation: someone had filled in the front yard and raised the retaining wall! The trees, unfortunately, had not been consulted during this construction, leading to present-day unforeseen challenges.

Construction projects often focus on their objectives without considering trees’ biological needs, especially their roots. White oaks in particular do not respond well to changes in grade.

Maintaining the proper soil level around the trunk is crucial, and altering the grade around any tree there fore requires caution. My recommendation to this client is to excavate a three-foot area surrounding each trunk and to build small retaining walls to prevent soil from eroding back into place while they make final plans for this portion of the yard. Ensuring proper water drainage
and reducing soil compaction are next on the list of priorities. In the meantime, I am prescribing a growth regulator and root stimulants to help the trees recover from the stress evident last year.

If your tree resembles the straight sides of a telephone pole with no outward “root flare” at the ground level, take action. Reach out to your ISA Certified Arborist to inquire about excavating the root area to evaluate your tree. Any historical information you can provide may help unravel your own trees’ mysteries!

A special thank you to the Galante family of Pewaukee for permission to use their photographs and for entrusting us with the care of their trees. Here’s to uncovering the hidden stories beneath our trees, and to ensuring their health for generations to come.

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