10/09/2026
A girdling root on a main buttress root is one of those slow failures that looks fine until it isn’t.
When a root wraps around the trunk or another major root at the flare, it doesn’t just “grow nearby.” As both thicken, that root acts like a tourniquet. It compresses the cambium, pinches the path for water and sugars, and keeps the flare from flaring the way it should. The tree can still leaf out for years. Then the canopy thins on one side, growth slows, the trunk looks pinched or flat where the root crosses, and decline shows up suddenly.
Most of these start at planting: a circling root that never got cut, the tree set too deep, or soil and mulch piled over the flare so roots grow up and around instead of out. By the time the canopy looks sick, the constriction has often been there a long time.
If you can see the root flare, look for a root crossing the trunk or another buttress and biting in. Don’t just chop at it with a shovel. A main girdling root sometimes has to come out in stages, and sometimes the damage is already structural. Caught early, removal can save the tree. Left alone, that root usually wins.
Right tree, right depth, flare visible at the soil line. Most girdling problems are planted in, not inherited.