Walk around your yard and look at the base of your trees. Does the trunk widen where it meets the ground, with a few surface roots fanning out? Or does it go into the soil like a telephone pole, straight down, no widening at all? If it's the second one, your tree was planted too deep, and that quiet mistake is one of the most common reasons trees in North Texas slowly decline and die.
The widened base of the trunk is called the root flare, sometimes the root collar. In a healthy tree it sits at or slightly above the soil line. Keeping that flare exposed is one of the simplest, most effective things you can do for a tree, and checking it takes about five minutes.
What the root flare is, and why it needs air
The root flare is where the trunk transitions into the root system, and trunk bark isn't built to live underground. When the flare is buried, bark stays wet, which invites decay organisms and fungal problems. Roots near the surface also need oxygen, and in our heavy Texas clay, which drains poorly and compacts easily, a buried flare suffocates feeder roots that were never meant to live under packed soil.
Worst of all, a buried trunk encourages girdling roots: roots that circle the trunk instead of growing outward. As they thicken over the years, they strangle the tree from below, cutting off water and nutrient flow. The tree responds with classic slow-decline symptoms: sparse canopy, early leaf drop, dieback at the top. By the time those show up, the damage is years in the making.
Why flares get buried in North Texas yards
Deep planting usually happens at the nursery or during installation. Trees sit in pots where extra soil has crept above the flare, and installers plant the root ball at pot depth instead of digging down to the flare. In new subdivisions around Melissa, Anna, Princeton, and McKinney, we see builder-planted trees sitting two to six inches too deep.
It also happens to established trees. Soil gets graded around them during construction or landscaping, raising the grade against the trunk. And the infamous mulch volcano, mulch piled against the trunk, effectively buries the flare one season at a time.
The 5-minute flare check
Grab a hand trowel or even a large spoon and head to the base of the tree:
1. Scrape back the mulch and soil. Pull mulch away from the trunk and gently scrape soil from the base until you see the trunk widen or spot surface roots radiating outward. Work gently. Small roots near the surface are fragile.
2. Find the widening. The flare should look like the tree is standing on the ground, with a visible taper. If the trunk stays the same diameter straight down for several inches, it's buried.
3. Check all the way around. Soil is sometimes mounded on one side only, where a bed was edged or a walkway regraded. Check several points around the trunk.
4. Note what you find. A flare within an inch or two of the surface is normal. Several inches of burial is a real problem worth fixing. If you find roots circling the trunk instead of heading outward, note those too.
How to fix a buried flare
For an inch or two of excess soil, you can do this yourself. Carefully remove the extra soil by hand down to the first structural roots, taking care not to scrape or nick the bark. Once the flare is visible, keep a mulch ring two to three feet out from the trunk but pull it several inches back so nothing touches the bark. If you find small circling roots while you're down there, snip them with clean, sharp pruners and disinfect the blades between cuts. This simple tree diagnosis step solves a surprising number of mystery-decline cases.
Do not add soil to make the grade "look right," and don't re-bury the flare under fresh mulch. The flare belongs in the air. Our guide to trees planted too deep covers how the burial usually happens at planting, and the slow decline that follows it.
When it's a job for a pro
Call an arborist or tree service when the burial is several inches deep, when girdling roots thicker than about an inch are wrapped tight against the trunk, or when the tree already shows significant decline: thinning crown, trunk decay, or fungal conks. Professionals excavate with an air spade, a tool that blows soil away with compressed air without damaging roots.
If decline has gone too far and the tree is structurally compromised, removal may be the honest answer. Learn when removal is the right call, or read about proper pruning to keep the rest of the canopy in good shape while the roots recover.
Common Questions
My tree was planted years ago. Is it too late to expose the flare?
No, it's rarely too late. Root collar excavation can be done on established trees of any age, and trees often respond quickly once the flare gets air and water can drain away from the trunk. The sooner you do it, the better the recovery.
Can I just mound soil or mulch around the base to make it look right?
No. Adding soil against the trunk makes the burial deeper, and piled mulch against the bark traps moisture and invites decay. Mulch should sit in a wide ring that starts several inches away from the trunk, not touching it.
How deep is too deep?
The top of the root flare should sit at or slightly above the surrounding soil level. One or two inches of excess soil is common and usually fixable by hand. Several inches of burial, or soil piled against the trunk of an older tree, calls for a professional with an air spade.
Related: Is your tree dead or just dormant? How to tell, and what to plant under your North Texas trees.