---
title: Root Flare: The Base of the Trunk Explained
url: https://battleborntreeservice.com/glossary/root-flare/
business: Battle Born Tree Service
address: 6301 US Highway 50 East, Carson City, NV 89701
phone: 775.232.8243
hours: Office Monday-Friday 8:30 am-5:00 pm; phones answered seven days a week; 24-hour emergency service
credentials: ISA Certified Arborist WE-11728A on staff; Nevada Business License # 20131580674; fully insured
type: Tree service (removal, crane work, pruning, stump grinding, defensible space, snow removal, firewood)
---

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- [Arborist glossary](https://battleborntreeservice.com/glossary/)
- Root flare

# What is the root flare?

The root flare is the place at the base of a tree where the trunk widens as it turns into the main roots. On a healthy tree it is visible at the soil line; a trunk that goes straight into the ground like a telephone pole is a flag.

## How to recognise it

Look at the base of the trunk. The bark should swell outward as it meets the ground, in a skirt that grows wider toward the soil. If you cannot see it, the flare may be buried under soil, bark mulch, sod or rock, or the tree may have been set too deep when it was put in the ground. Mulch piled against the trunk in a cone hides the flare and keeps the bark damp.

A buried flare also hides what the arborist most wants to see: cracks, decay, [conks](https://battleborntreeservice.com/glossary/conk/), and [girdling roots](https://battleborntreeservice.com/glossary/girdling-root/) circling the trunk.

## Why it matters in Northern Nevada

Lawns and irrigation are why so many valley trees live here, and they are also why soil and sod creep up trunks over the years. Landscape work, new sprinkler lines and re-grading can bury a flare that was visible when the tree was young. The result can be slow decline that owners put down to drought.

Large trees are judged first at the base. An arborist looking at a cottonwood, an elm or a pine near a house checks whether the flare is sound, because the base carries the weight and sets how the roots hold.

## What an arborist does about it

The arborist finds the flare, often by gently probing, and checks it for decay and for roots that cross it. If the flare has been buried, exposing it is careful work, so roots are not damaged. In some cases a lowered grade is not possible, for instance where it would expose structural roots to damage, and the arborist says so.

The flare is part of every assessment Battle Born's certified arborists do before a pruning or removal estimate.

### Sources

- [International Society of Arboriculture, Trees Are Good: New Tree Planting (brochure)](https://www.treesaregood.org/Portals/0/siteContent/pdf/Web%20TAG%20brochures/TAG_CBweb_New%20Tree%20Planting_v3.pdf) (read October 17, 2026)

### Talk to the office

[775.232.8243](tel:775.232.8243)

| Monday to Friday | 8:30 am - 5:00 pm |
|---|---|
| Saturday and Sunday | Office closed, phones answered |

Phones answered seven days a week. 24-hour emergency service.

[Free estimate](#quote)

### Keep reading

- [Arborist glossary](https://battleborntreeservice.com/glossary/)
- [Warning signs before a tree fails](https://battleborntreeservice.com/guides/warning-signs-tree-failure/)
- [Root and trunk decay](https://battleborntreeservice.com/tree-guide/root-and-trunk-decay/)
- [Arborist consultation](https://battleborntreeservice.com/tree-services/arborist-consultation/)

## See also

[Girdling root](https://battleborntreeservice.com/glossary/girdling-root/) [Buttress roots](https://battleborntreeservice.com/glossary/buttress-roots/) [Root plate](https://battleborntreeservice.com/glossary/root-plate/) [Conk](https://battleborntreeservice.com/glossary/conk/)

## Where you will see it on this site

[How deep do you grind a stump?](https://battleborntreeservice.com/faq/stump-grinding/how-deep-do-you-grind-a-stump/) [How to tell if a tree is dead or dying](https://battleborntreeservice.com/guides/is-my-tree-dead-or-dying/) [Ash trees: Modesto, Raywood and green ash](https://battleborntreeservice.com/tree-guide/ash/)