By Harry Carter
ISA Certified Arborist®
November 26, 2024
As an ISA Certified Arborist® and avid tree climber, I find myself in many different trees and looking down over elegant landscapes, playgrounds and houses. I work in many trees requested to be removed by their owners due to concerns regarding potential tree failure and property damage. Although some of these trees may have defects such as poor branching habits, cracks, codominant stems, and more, there are tree preservation solutions that can work to keep them upright, healthy, and stable! Proper tree care including tree cabling can go a long way toward maintaining your big, green giant!
Trees are such a beneficial part of your property whether it’s the shade the canopies can provide to your home or the aesthetics of the wind blowing through their leaves. Unfortunately like everything else, these beautiful organisms can have their problems, especially as they mature and grow larger. These giants need some help to stick around just like me and you. Defects left unattended such as included bark or wounds can create weaken unions in your tree. Luckily, there are solutions to help keep your canopy stable! Cabling the tree creates strength from above to protect the tree and provide it with a long-term health plan to keep it together. Paired with a good pruning regimen and tree wellness prescription, we can help to keep the tree happy and healthy. Russell Tree Experts offers two types of cable systems that each have their own supportive benefits!
Tree Candidates for Cabling
You might ask yourself “Why would my tree require cables?” Though trees are strong and beautiful, sometimes they are imperfect and grow in funky, different ways to reach sunlight more or to grow away from a structure, often resulting in poor branching habits or defects such as cracked stems, codominant stems, or included bark. Codominant stems are two similarly sized stems growing away from each other, causing a v-shaped crotch that is prone to splitting. Included bark is bark trapped and growing between two branches or unions. This bark acts as a wedge and makes the crotch more prone to splitting.
Other trees that would benefit from cabling are trees damaged from a storm, impacted by an insect or disease, or that have been pruned improperly away from a utility line. These scenarios often leave behind defects and/or wounds, leaving the tree in a weakened, vulnerable state. Wounds take time to compartmentalize (compartmentalization is how trees heal) and sometimes the tree doesn’t have the resources to close the wound quick enough before decay starts to creep into the heartwood of the tree. Cabling can indirectly assist trees in compartmentalization by supporting particular limbs and giving the tree a better chance of compartmentalizing over the affected area before failure. Limb failure can be the end of it for a tree and potentially damage targets below such as turf, concrete, cars, or structures. Supporting these works of art nature created is an essential part of tree preservation in arboriculture and protecting both your property.
What is Tree Cabling?
Tree cabling is the installation of hardware in a tree to provide supplemental support to weak sections at risk of failure. This will limit movement of branches and help support loads. This is especially beneficial during adverse weather conditions such as heavy rainstorms, harsh wind events, and blizzards. There are two general cabling options: Static and dynamic. Both options have their advantages and proper use cases.
Static Cable
Static cable
A static cable is an extra high strength, galvanized steel cable. Russell Tree Experts commonly uses a 5/16 inch cable with a minimum breaking strength of 11,200 pounds, but other sizes exist. This provides low to minimal stretch or movement. A static cable is an ideal choice for a tree containing moderate to severe damage such as a tear, split or crack. Using an analogy of a broken bone, this is similar to using a splint to prevent the limb from moving in a harmful way. With a static cable, the arborist drills a hole through the stem, terminates the cable using a wedge grip device, and traverses the canopy to the other side to drill a second hole and terminate the system using a come along to tension the cable to make the support more rigid. Although this method of cabling is intrusive, it is much stronger than dynamic cable and will allow less movement. Sometimes this is necessary in order for a damaged tree to stay together.
Dynamic Cable
Dynamic cable
The second option is a dynamic cable. As the name suggests, a dynamic cable allows the tree to sway with the wind and work together to stay upright. A dynamic cable can be seen as a preventative option to help keep the tree together before a split occurs. This is beneficial for trees with poor branching habits or codominant stems. One of the benefits to a dynamic cabling system is allowing reaction wood to strengthen over time, thus making the tree healthier overall. Reaction wood is wood that has formed due to stresses like leaning or bending in order to offer additional strength and support. It is less intrusive to the tree and does not require any drilling. Dynamic cabling is also beneficial for a union with minor damage that is at risk of separating from the rest of the tree. This is an aid to help the tree compartmentalize and work toward creating good structure. Continuing on with the broken bone analogy, this would be similar to using a sling that allows for a little more movement than a splint.
This cable system is a hollow braid rope that is much softer and does not require the arborist to drill into the tree. The dynamic cable is similar to a static cable in that it must be terminated, but the arborist makes a loop and splices the rope together to make a loop on the limb. Afterwards, the arborist traverses the canopy to make another loop and hand tightens the line to achieve the proper support the tree needs.
Improper Cabling
If a cable is installed correctly, it shouldn’t cause any damage or girdle the tree. A static cable arguably harms the tree during the drilling process, but it should only be performed if the end result is a net positive towards a tree’s health through adding additional support. In the case of a dynamic cable, girdling can occur when a cable loop is wrapped extremely tight around a stem, choking it out and restricting resources to the upper portion of the canopy above the cable. This can happen when a cable has not been inspected/adjusted for multiple years and the tree continues to grow. As a result, the bark and even the cambium layer can be damaged.
An example of a girdled dynamic cable. ISA Board Certified Master Arborist® Jacob Nau does not approve.
Maintenance
After tree work occurs on a tree, the tree will react and adapt to the treatment slowly over time. Trees continue to grow and sometimes cables need to be adjusted to prevent girdling or to ensure correct placement in the upper 2/3 of the canopy from the union in question to work effectively. The International Society of Arboriculture recommends having cables inspected every 1 to 3 years. All cables should be inspected by a qualified arborist to check the tension and structure of the cable. Wildlife, weather, and UV degradation all play roles in the breakdown of a cable and should be considered by an arborist during an inspection.
If you suspect that your tree may benefit from cabling, the next step would be to have an ISA Certified Arborist® inspect your tree(s) and provide a second opinion. There is a chance that cabling may be recommended alongside other services such as pruning or bracing. The arborist should have a strong recommendation as to which cable would best support your tree.
Unfortunately, not all trees can be saved by cabling and in some cases, may require removal for safety purposes. With the proper tree candidate, tree cabling can be a good investment for both your tree and property. The science and art of tree preservation is very rewarding to the arborist as well as the manager of the tree. For a free tree work quote including cabling by one of our 20+ ISA Certified Arborists®, visit RussellTreeExperts.com/Quote or call (614) 895-7000!
ADDITIONAL ARBOR ED ARTICLES!
Sincerely,
Harry Carter I General Crew Leader, Russell Tree Experts
Harry has been with RTE since 2015! He is an ISA Certified Arborist® and TCIA Certified Treecare Safety Professional (CTSP)! Harry has his associate’s degree in forestry management from Hocking College. His favorite tree is the Ginkgo biloba. When he’s not up climbing in a tree, you can find Harry playing in the woods with his family, caring for his bonsai trees, ice climbing, or rock climbing!