Gardening Plant Problems

What Is Tree Girdling and How Bad Is It?

Plant labels possibly girdling a tree

The Spruce / David Beaulieu

Unfortunately, in tree-care terminology, "girdling" is a word used in two different ways. This means that, unless a context is provided, the reader may not immediately be clear on how the writer is using the term. To help you avoid confusion, a full definition (incorporating both meanings) will be given below.

Girdling as an Intentional Act

Girdling can be a management technique. It severs the bark, cambium, and sometimes the sapwood in a ring that encircles the trunk of a tree. In this sense, the word usually refers to the intentional killing of a tree.

Many beginners bristle at the very mention of intentionally killing a tree. So some explanation is required. What possible reason could there be to girdle a tree in this way?

Well, let's say that you own (but do not regularly live at) an extensive piece of property that borders upon the forest. On one portion of this property, your plans are to eventually have an open space of lawn area. In the meantime, you need to keep the brush down in this spot as best you can. If a sapling (that is, a young tree) begins to emerge, and you do not have time right away to cut it down, you may want to stop it in its tracks by killing it. So you girdle it. Later, at your leisure, you can remove it.

Standing dead wood (i.e., a girdled tree) is a critical part of an ecosystem. Standing dead wood provides habitat and food sources, and replenishes nitrogen. Often trees are girdled just to manage forests.

Tip

If you want firewood but don't want to have to keep stacks of wood for years before you can use it, girdling is a great option. A girdled tree can dry and season while standing, then be ready for use by the time you cut it down.

When Girdling Is Accidental

But it can also refer to the strangling of a tree (or shrub) branch or tree trunk by something wrapped around it, which chokes off the flow of nutrients. This is commonly caused by humans (accidentally), by vines, or even by a tree's own roots.

When humans are the culprit, it is often because they have tied a material onto the plant. For example, it may be a wrap used in grafting or a plant label (either the plastic-strip type that wraps around branches or the kind affixed with a string). Leaving such labels on your plant for too long after bringing it home from the nursery or garden center often turns out to be that sort of common landscaping mistake that you kick yourself for later.

Before you know it, the branch will increase enough in girth for girdling to occur. If you need to keep the plant marked with some kind of label, devise your own, instead. The key is to make sure that any label you attach to a tree branch is suspended loosely from the tree, so as to avoid all possibility of future girdling.

Fun Fact

Girdling can result when a strong vine vigorously twines itself around a tree. For example, the vine bittersweet will often girdle a tree in a fashion reminiscent of a python strangling its prey.

Finally, an instance of a tree's own roots girdling it is characterized by Missouri Botanical Garden (MBOT) as a "stem girdling root circles or partially circles the base of a tree at or just below the soil surface."