How do you girdle a tree


What Is Tree Girdling and How Bad Is It?

By

David Beaulieu

David Beaulieu

David Beaulieu is a landscaping expert and plant photographer, with 20 years of experience. He was in the nursery business for over a decade, working with a large variety of plants. David has been interviewed by numerous newspapers and national U.S. magazines, such as Woman's World and American Way.

Learn more about The Spruce's Editorial Process

Updated on 06/21/22

Reviewed by

Andrew Hughes

Reviewed by Andrew Hughes

Andrew Hughes is a certified arborist and member of the International Society of Arborists specializing in tree heal care. He founded and runs Urban Loggers, LLC, a company offering residential tree services in the Midwest and Connecticut.

Learn more about The Spruce's Review Board

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."

Tree Girdling – Halton Region Master Gardeners

haltonmastergardeners

Cathy Kavassalis – Halton Master Gardener

Girdling, also called ring-barking is the loss of a strip of bark from around a branch or trunk of a woody plant. The width and depth of the strip, the age of the plant, the time of year, the presence of disease and other environmental factors, determines if a tree can recover from such an injury. Significant loss of bark can leave a plant open to desiccation and infection. If vascular tissue is also lost, the plant may starve. While plants have some capacity to recover from minor injuries, serious girdling injuries can kill.

Girdling can happen through neglect as in photo on left, above (shutr.bz/2TMSD0S) AND with Rabbit damage -Photo: http://bit.ly/2wBqh2N

The bark of a tree, is made up of many layers. The outer layer is a tissue called phellem or cork. The cells are dead but they form a protective barrier for the plant. Just inside the cork layer, is a single layer of cells called the cork cambium or phellogen. (This is a layer of undifferentiated cells, called meristemic cells, which produce the cork on the outside and in some species a layer of phelloderm on the inside). If only the outer bark is lost, woody plants can typically recover with a bit of extra attention to watering.

However, just inside the outer layer is secondary phloem tissue. This is a very important part of a plant’s vascular system. The phloem is composed of various specialized cells that circulate nutrients like sugars and starch as well as other important compounds like hormones. If disrupted the plant can no longer move these important materials to where they are needed.

Read: Preventing Girdling

If the vascular cambium or some of it has been undamaged, the plant may recover some function. Like cork cambium, vascular cambium is a single layer of meristemic cells that can differentiate to form more specialized tissue. This layer is important, not only because it produces secondary phloem, but also because it produces xylem. Secondary xylem tissue is produced just inside the vascular cambium. This tissue has a distinct construction that allows water and minerals to move through it from the roots all the way up the trunk and to the leaves. The xylem tissue is referred to as sapwood. (As sapwood ages and the xylem gets clogged with gums and resins it no longer transports water, it can become distinctly coloured, and is often referred to as heartwood.

Read: Why some trees are ‘girdled ‘on purpose’! (page 14)

The heartwood provides structural support for trees, but the tissue is dead and no longer functions). Tree rings reflect the seasonal variation in the development of xylem tissue.

Deer and or squirrels and rabbits often remove strips of bark over the winter. If this is just a small portion of the bark, woody plants can completely recover. However, if the plant is ring-barked with 100% disruption of phloem tissue, water can move up to new growth, but as leaves become photosynthetically active, they will not be able to move sugars and starches back down to support growing roots. The trunk or branch above the ring will swell as compounds accumulate. Tissue from the vascular cambium and cork cambium below and above the cut will begin to differentiate forming callus tissue followed by woundwood. If the width of the ring is narrow, a young actively growing tree may be able to seal over an injury, and reconnect phloem. But if the ring is wide or the tree is old, the injury may not be bridged by woundwood.

In such cases, artificial bridges can be created using grafts from thin branches. This is a tricky operation, but can be tried if the alternative is loss of the tree. See links below.

A seriously injured tree or shrub may try to send up suckers or alternative shoots from below the point of damage. Removing the damaged trunk or branch can encourage the growth of an alternative leader and may reduce the risk of infection if done carefully.

Further reading:

  • Moore, G.M. 2013. RING-BARKING AND GIRDLING: HOW MUCH VASCULAR CONNECTION DO YOU NEED BETWEEN ROOTS AND CROWN? https://treenet.org/resources/ring-barking-girdling-much-vascular-connection-need-roots-crown/
  • Moore, G.M. & McGarry, P.G.. (2017). Investigation of the potential for bark patch grafting to facilitate tree wound closure in arboricultural management practice. Arboriculture and Urban Forestry. 43. 186-198.
  • López, Rosana & Brossa, Ricard & Gil, Luis & Pita, Pilar. (2015). Stem girdling evidences a trade-off between cambial activity and sprouting and dramatically reduces plant transpiration due to feedback inhibition of photosynthesis and hormone signaling. Frontiers in Plant Science. 6. 10.3389/ fpls.2015.00285. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4413673/
  • Pepper, H. (2008). Girdling, Constriction and Ring Barking. Trees in focus https://www.trees.org.uk/Trees.org.uk/files/be/be635d9d-5a6e-464a-a6b7-0ca1e85f1dba.pdf
  • Luley, J. (2016) Biology and Assessment of Callus and woundwood. Arborist News https://www.treerot.com/wp-content/uploads/2016/04/Arborist-News-Callus-and-woundwood_Luley.pdf
  • Tree Biology, and CODIT ISA‐T Oak Wilt Certification Training David Appel isatexas.com/wp-content/uploads/2017/05/2017-Appel-OWQ-CODIT.pdfLearn more about tree ring formation and xylogenesis here:Rathgeber, Cyrille & Cuny, Henri & Fonti, Patrick. (2016). Biological Basis of Tree-Ring Formation: A Crash Course. Frontiers in Plant Science. 7. 10.3389/fpls.2016.00734. https://www.researchgate.net/publication/303535986_Biological_Basis_of_Tree-Ring_Formation_A_Crash_Course )

Some Videos:

  • Nature Insights – Tree Ringing Experiment on Birch, Willow and Alder https://www.youtube.com/watch?v=FOjJBtOANck
  • Repairing a girdled deer damaged tree on a Norfolk Pinehttps://www.youtube.com/watch?v=gkgZktIPmr0Plant Transport Xylem and Phloem, Transpiration [3D Animation] https://www.youtube.com/watch?v=CmBDVIUB19g
  • Plant Nutrition and Transport – Andersonhttps://www.youtube.com/watch?v=bsY8j8f54I0

Categoriesgarden care, pests, treesTagsbark, cambium, damage, phloem

What is girdling tree and how bad is it?

Home basic household items and appliances What is girdling tree and how bad is it?

Unfortunately, girdling is used in two different ways in tree care terminology. This means that if no context is provided, the reader may not immediately understand how the author is using the term. To help you avoid confusion, the full definition (including both meanings) will be given below.

Girdling as a deliberate act

According to the USDA Forest Service, one use of the term is: "Girdle encircles bark, cambium, and sometimes sapwood in a ring that completely encircles the trunk of a tree." In this sense, the word usually refers to the deliberate killing of a tree.

Many beginners get upset at the mention of intentionally killing a tree. So some explanation is required. What possible reason could there be for girdling a tree in this way ">

Okay, let's say you own (but don't regularly live in) a large piece of property that borders a forest. In one part of this property, your plans are to eventually have an open space (perhaps for a lawn). In the meantime, you need to keep the brush in this place as best as possible. If a sapling (i. e. a young tree) starts to spawn and you don't have time to cut it down right away, you can stop it by killing it. So you gird it. Later, at your leisure, you can delete it. This would be an example of a legitimate reason to kill a tree.

When girdle is extra accidental

But it can also refer to suffocating a tree branch (or shrub) or tree trunk with something wrapped around it that stifles the flow of nutrients. It is usually caused by humans (accidentally), vines, or even the tree's own roots.

When humans are the culprit, it is often because they have attached the material to the plant. For example, it could be a wrapper used in grafting, or a plant label (either a plastic strip that wraps around branches or one that is attached with string). Leaving such labels on your plant too long after it's been delivered home from the nursery or garden center often turns out to be such a common landscaping mistake that you kick yourself for later.

Before you know it, the branch will grow in girth enough to form a girdle. If you need a plant to be marked with a label, come up with your own. The main thing is to make sure that any tag you attach to a tree branch is freely suspended from the tree to prevent further girdling.

Interesting fact

Girdling can occur when a strong vine is vigorously weaved around a tree. For example, the bittersweet vine often girdles the tree in a way that resembles a python strangling its prey.

Finally, the case of girdling the tree's own roots is characterized by the Missouri Botanical Gardens (MBOT) as "the root of the girdling stem surrounds or partially surrounds the base of the tree at or just below the soil surface."

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How to hang a birdhouse without damaging the tree

Category wildlife Animals | October 20, 2021 21:41

Birdhouses will be a wonderful addition to the yard or garden. They can be aesthetic and, depending on the type and location of the birdhouse, can attract a wide variety of birds. Although the first place to consider when setting up a birdhouse is birds, you should consider a few other organisms as well.

The first is the tree itself. It is important to consider how you set up or hang your birdhouse, as well as the potential harm some methods can do to the tree.

The second organisms are, well, actually several organisms: carnivorous animals like cats, raccoons, snakes and squirrels that would like nothing more than to sneak into a birdhouse for a quick bite to eat or turn the house into their own.

Consider a bird and a tree

The usual tilt when attaching a birdhouse to a tree is with a nail or screw. After all, this is how we attach most things to wood surfaces. However, not every problem needs a hammer or a nail. In fact, such a slope can potentially cause real harm to the tree.

As Mickey Merritt of the Texas Forest Service explained in the Houston Chronicle in 2007, nails and screws that penetrate the outer bark can damage the cambium, the area immediately below the bark. This is the space where cells divide rapidly and help the tree grow. Other parts of the tree, including the folem, the tissue of the tree that transports the sugars that produce photosynthesis, and the xylem, the tissue system responsible for transporting water from the roots to other parts of the tree, can also be damaged by nails or screws. Nails and screws not only cause physical harm, but also create openings for insects and disease to enter.

Some trees are able to recover from these stab wounds. Upon entering the tree, a chemical reaction is initiated which essentially seals off the rest of the tree from the injured area, preventing any disease and rot from spreading. However, new wounds continue to trigger this process, and according to Merritt, it may take as little as 10 holes to destroy a tree, depending on their location.

A nail hurts wood as much as it hurts you. VADL / Shutterstock

So, now that the nails don't fit, attaching the birdhouse to the tree is a bit more work than getting the nail the right height. Arborist Now recommends any flexible flat nylon strap. A fabric Velcro glued to the sides of the birdhouse and outward-facing straps will allow you to glue the birdhouse to the tree without damaging it. You will need to periodically check the tree's growth to make sure you are not girdling it. Nylon straps, which also have buckles and buckles, can help with this task because they are easy to adjust.

SFGate has a more detailed way to hang a birdhouse on a tree that sounds a little more secure than fabric fastener and glue. You'll need eye screws or hooks, rubber wire conduits and elastic cords, and some precise measurements to make sure everything is exactly the way you want it.

Remember that in all cases you need to think about what kind of bird you want to attract. Different birds have different height requirements, and some birds are very territorial, so setting up too many birdhouses can cause fights. Some will want the house to wobble, while others may see this instability as a deal breaker when choosing a house. Installing birdhouses in a way that does not damage the tree will also allow you to easily move birdhouses to different locations and heights without having to make more holes.

Consider predators

A birdhouse attached to a pole protects it from predators, and many birds won't mind placing it. Jörg Luhe / Shutterstock

Birds, given their many years of evolution, are quite good at building their nests away from predators. However, a birdhouse made and installed by man cannot be treated the same way.

Now, if you're really serious about not hurting the tree with the birdhouse, but still want a birdhouse, just don't put it on the tree. Trees provide predators with plenty of opportunities to get to the birdhouse. To ensure the safety of the birdhouse on the tree, it is necessary to cut the branches away from the birdhouse. Planting thorny bushes at the base of the tree to prevent anyone from climbing up the trunk will also help deter predators.

If you need a predator-proof birdhouse, consider placing the birdhouse elsewhere. Cranmer Earth Design offers several suggestions:

1. Metal pole. When it comes to climbing, it's not much harder than a metal pole. You add a baffle and predators that are happy climbing need to be thwarted, especially if there's nothing nearby to jump onto the baffle.

2. Slippery facade of the building. Okay, maybe this will be harder than a metal pole. However, while you can often easily mount a birdhouse on a pole, installation on a slippery facade will be difficult. Also, you need to consider the color of the building as well as the direction it is facing to avoid absorbing or exposing too much heat from the sun.

Brick is difficult for predators to climb, but it can warm up quickly.xlibes / Shutterstock

3. Brick buildings. Brick is not easy to climb, and unlike wood, drilling through brick won't hurt anything. As with the facade of a building, avoid the sides of the building that receive a lot of sunlight.


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