"Cabling" is the use of cables to stabilize an established tree growing in a manner that is not sustainable if left uncorrected. Cabling is often employed by arborists or other skilled tree service professionals to save a specimen tree. If cabling is not done properly, girdling can result; that is one reason why cabling trees are not considered a task for untrained homeowners to do on their own. An arborist will know where and how to position the cables properly.
Cabling is sometimes used to save a tree with a split trunk, for example; without cabling, such trunks will eventually be torn apart. Another use of cabling is to support a large branch that is growing at an awkward angle. In the latter case, the operation is undertaken as a preventive measure.
When such an operation is called for, it can be performed with a variety of goals in mind, such as:
- To save the health of the tree (a compromised trunk or branch is an "open wound" that invites harmful fungi into the insides of your specimen).
- To preserve its appearance (a tree that has lost a major limb may forever afterward appear lopsided).
- If it is a large tree located right near a home, cabling could be necessary in order to keep a large branch from falling on the house, thereby causing property damage.
- If a large, unstable branch is hanging over a walkway, it poses a risk to anyone using the walkway. This includes not only you and your family but also guests―who could sue you for injuries should the branch ever fall on them.
How Cabling Is Done
Cabling is achieved by drilling holes in the trunk or branches of the tree in question, into which the arborist will insert the cable. The cable is secured so as to keep it tight. Do not confuse cabling trees with staking trees, which is an operation that involves anchoring the tree to the ground. Support in cabling, by contrast, occurs totally above the ground.
Moreover, tree staking is meant to provide merely temporary support, while cabling is meant to provide stability over the long haul (often for the rest of the tree's life). A young tree (or "sapling") may be staked in order to keep it from starting out its life crooked; as soon as it is successfully established, the "training wheels" (that is, the staking equipment) are removed. By contrast, if a tree has been cabled because one of its branches is growing at an awkward angle, most likely that wire will stay there permanently. The angle will always be unsustainable (on its own), so there would be little reason to remove the supporting wire.
"Guying" is yet another technique used to stabilize trees and can be thought of as a cabling method in which the cable is anchored to the ground (as in tree staking) or to another tree.