girdling

Girdling is the removal or damage of a continuous strip of bark around the circumference of a plant stem or root, typically including the phloem and often the cambium. This interrupts the downward transport of sugars from the leaves to the roots, weakening tissues below the girdle and starving tissues above it. If the girdle is complete, death of the portion of the stem or tree above the wound is likely over weeks to years; xylem transport remains possible, but the supply of sugars is cut off.

Girdling can be deliberate or accidental. In horticulture and forestry, ring-barking or girdling a branch or trunk can temporarily reduce vigor, redirect growth, or promote fruiting, though success varies. More commonly, girdling occurs unintentionally when animals rub or chew bark, when mowers or equipment scrape around a base, or when vines, wires, or encircling roots constrict a stem. Girdling roots, where roots wrap around and constrict a trunk, are a serious problem in established trees and shrubs.

Symptoms include thinning or dieback of the crown above the girdle, cracking bark, and a distinct constriction at the ring. In the absence of intervention, the affected part may die and the tree may fall or become structurally weak. Management focuses on removing constricting materials, promoting recovery where possible, and preventing future girdling by careful pruning, fencing, or root management.