Excavating / Exposing Root Flares

Buried root flares is a common problem I run into. Probably, the main reason this is a prevalent problem is because most people don’t know what a root flare is or why it is an important part of the tree. The improper burial of trees’ root crowns results from various scenarios in my experience: construction processes, overzealous mulching, poor drainage and bad landscaping to name a few. So, what is a root flare? Why is it important? And, how do we excavate them after they’re buried? These are the important questions.

Let’s start with, “What is a root flare?” This is the part of the tree where the trunk and roots meet each other. It is an anatomically transitional zone. The picture shows what a root flare looks like. The roots and trunk are built differently.

Burying the trunk of a tree is a ticking time bomb. Depending on the species of the tree and the content of the organic material contained in the soil, the process of tree decline takes anywhere from 5 to 35 years. The bottom line is that the roots have mechanisms that prevent them from rotting out from natural decay causing organisms in the soil. The trunk does not. If you bury the trunk; it will eventually begin to rot.

If your tree is already buried, and it is still alive, you should excavate the root flares. The idea is that the trunk needs to be exposed to the air. If you can visibly see the roots tapering out of the base of the trunk, you are there. It’s not important to excavate any particular size area around the trunk. You just need to make sure dirt isn’t physically touching and that you leave the tree so that the dirt you excavated doesn’t fall right back in.

The best way to excavate the soil is with an airspade. An airspade is a high powered air compressor that blows away the dirt without cutting through tree roots. This tool is generally not readily available to rent so you’d need to hire a professional arborist to do it this way. If you are performing the excavations yourself, use a small shovel, metal rake and brush. Be careful not to swing a shovel or pick violently into the ground very near the base of the tree. Exposing the root flare has no value if you completely destroy the roots in the process! Power washers can be dangerous because the water will cut through the bark of the roots.