An Introduction to Supplemental Tree-Support Systems, Part 1: The Need for Supplemental Support

At TCI EXPO ’23 in St. Louis, Missouri, we hosted a training on the show floor called “Cabling Made Easy.” With the assist of our training partner, Thomas Paine, CTSP, we demonstrated our preferred method of cable installation and attempted to explain the merits of this method. Many attendees approached us afterward to ask all sorts of questions about cabling and bracing. Though we were ill equipped to provide sufficient answers to everyone’s questions, we were able to share many of the “basics” with the arborists looking to expand their knowledge and professional arsenal. This article is the first of a four-part series for TCI Magazine aimed at continuing that discussion and answering more of those questions.

Matt Bronakowski with Rooted Arbor Care installs a dead end on a cable.
Matt Bronakowski with Rooted Arbor Care installs a dead end on a cable. All photos courtesy of Rooted Arbor Care.
A mechanical support system might have saved this tree. Instead, large ratchet straps or chains and chain binders can be used to temporarily mitigate the risk of continued mechanical failure prior to removal.
A mechanical support system might have saved this tree. Instead, large ratchet straps or chains and chain binders can be used to temporarily mitigate the risk of continued mechanical failure prior to removal.

This series will provide a general overview of tree structural-support systems.

It certainly will not be exhaustive, but it is our hope that we can deliver some palatable information that will help you expand your ability to serve your clients. Much of what we are going to share comes from our own catalog of experience and knowledge, but we also will tap into the minds of some of the field’s best practitioners.

In this series, we will discuss some of the methods of cabling, bracing, guying and propping, and we will look at some tools used to perform these tasks. We will conclude the series with some insight into how providing these services – whether as an independent contract arborist, business owner/operator or sales arborist – can help generate a new revenue stream while also providing your clients with a specialized service that fewer and fewer companies provide.

Before we can get to all of that, though, we need to cover the why behind installing structural-support systems.

Need for structural-support systems

As arborists, we prune to promote tree health and mitigate known risks. Risk-mitigation pruning encompasses the removal of deadwood, removal of poor branch unions, clearance pruning for pedestrian and vehicular traffic and targeted pruning for weight or length reduction.

Despite our best efforts, we often cannot mitigate enough risk by pruning alone. Sometimes we need to augment our risk-mitigation strategies by installing cables, guys, rods and props. These mechanical interventions are either installed proactively to promote the health, safety and longevity of a tree, or reactively to help alleviate acute mechanical concerns.

Why cable or brace?

Proactive installations are carried out for both prevention and protection.

Multi-leader trees often display poor growth habit and may be encumbered by bark inclusions, which are relatively good indicators of future mechanical failure. Codominant growth habits are especially concerning for trees that do not typically display multi-leader growth. Pin oaks and autumn blaze maples are two examples of trees that commonly display codominant growth habits and consequently succumb to mechanical failure resulting from severe bark inclusions.

Proactive cable or rod installations can often mitigate much of the risk associated with codominant stems and bark inclusions by eliminating much of the dynamic force that the compromised branch union incurs. Some trees pose inherently greater risk due to their proximity to high-value targets. In situations like these, structural-support systems may be the best risk-mitigation strategy to help alleviate the concern for mechanical failure that endangers people or property. Proactive installations are an excellent way to lower the risk for trees that may otherwise be considered for removal.

Reactive installations are implemented after a tree has begun to show signs of mechanical failure, such as cracking, splitting or tearing. Structural-support mechanisms can be installed to halt further mechanical failure when any remaining risk is deemed acceptable for the situation.

Ornamental trees are often reactively supported to maintain a landscape’s aesthetic or preserve a tree’s sentimental value. It is vital that, as the arborist, you present all the potential risks associated with reactive installations and ensure that you are not complicit in the potential injury to persons or property by performing a reactive installation that later fails.

Of all the supplemental-support systems, cabling and bracing often garner the most attention, but propping and guying are also very useful tools in any arborist’s toolbox.

This historic northern catalpa tree on the University of Lindenwood campus has several props supporting its limbs.
This historic northern catalpa tree on the University of Lindenwood campus has several props supporting its limbs.

Why prop?

Tree props are devices employed to support over-leveraged limbs. They are commonly found on fruit trees, ornamental trees or historic trees suffering from increased mechanical decline.

Andy Jones installing a five-sixteenths EHS (extra high strength) cable into a multi leader linden tree.
Andy Jones installing a five-sixteenths EHS (extra high strength) cable into a multi leader linden tree.

For example, the Angel Oak, a famous live oak on Johns Island, near Charleston, South Carolina, has been proactively propped to help ensure the tree remains structurally sound. Small ornamental or fruit trees are often propped to help support the immense weight increases they experience due to annual fruit or flower production.

Due to the reduced safety risk, propping is often a viable solution for both proactive and reactive installations.

Why guy?

Guys are typically proactively employed during tree installation. Ideally, newly installed trees shouldn’t require guying. But there are many considerations, such as species, soil type, drainage and several other environmental factors, that may hamper the early development of newly installed trees.
If a tree needs to be guyed due to environmental factors such as wind or soil conditions, it is important to keep in mind that this should be a temporary solution, and that the guy should be removed post-establishment to ensure that proper trunk taper is achieved.

“Figure 7.8.1 Bracing system configurations” from the new ANSI A300-2023 Tree Care Standards, published by the Tree Care Industry Association.
“Figure 7.8.1 Bracing system configurations” from the new ANSI A300-2023 Tree Care Standards, published by the Tree Care Industry Association.

Some trees may require the installation of tree-to-ground guy systems to reduce the risk of mechanical failure due to uprooting. Installation of a guy in a post-establishment setting does not guarantee mechanical longevity, so ensure that a thorough tree-risk assessment is conducted.

Conclusion

There are numerous reasons why arborists should consider implementing supplemental-support systems into their repertoire of specialty services. We look forward to unpacking some of the more commonplace situations in which these types of support systems should be employed, as well as the techniques and equipment used to install them, in the upcoming articles in this series.

Andy Jones, CTSP, is an ISA Certified Arborist, production climber and co-founder of Rooted Arbor Care, a TCIA member company based in St. Louis, Missouri. He is also a member of TCI Magazine’s Editorial Advisory Committee.

Nicholas Greenwood, CTSP, ISA Certified Arborist, is a climber in Chicago with Bartlett Tree Experts, an accredited 49-year TCIA member company based in Stamford, Connecticut.

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