Root Flare
/root flair/🌲 Arboriculture● Basic
Also known as: trunk flare, root collar
The root flare (also called trunk flare or root collar) is the transition zone between the trunk and the root system, visible as a widening at the base of the tree. A visible root flare indicates proper planting depth. When the root flare is buried — often from mulch volcano practices or planting too deep — it can lead to girdling roots, bark decay, and eventual tree decline.
Etymology
From Old Norse rōt (root) + Middle English flaire (to spread out)
Example
“Excavating the buried root flare revealed girdling roots that had been slowly strangling the trunk for years.”