Tree cabling and bracing add support to a tree with a structural weakness, such as a split fork or two heavy stems growing side by side, so it is less likely to fail. Cables limit how far the upper limbs can move, and steel rods pin together a fork that is already cracking. They manage a weakness; they do not repair a rotten trunk or save a dying tree, and a supported tree needs to be inspected regularly.
A cable is installed high in the crown, between two limbs or stems that are likely to split apart. Its job is to limit how far they can move away from each other in wind, ice or heavy wet snow, so the weak union is not pulled apart. The usual position is roughly two thirds of the way up from the weak fork, because a cable placed near the fork has little leverage and does not do much.
Modern flexible cables let the tree move naturally and only take the load at the extremes. That matters, because a tree that is held rigid builds less of the wood it needs to stand on its own. Support is meant to back the tree up, not replace its strength.
Bracing deals with a weakness lower down. A threaded steel rod is passed through the trunk or limb, across a crack or a tight fork, and fixed with washers and nuts to hold the two sides together. Rods are often used with a cable higher up, so the crack is held and the load above it is controlled.
Support only works if there is sound wood to attach it to. It is not the right answer when:
In those cases, removal is usually the safer call. A good arborist will tell you that, rather than install hardware on a tree that cannot use it.
Cabling and bracing are usually combined with pruning. Taking some length and weight off the heavy limbs reduces the load on the weak union, and it means the hardware has less to hold. Our guide to when to prune trees in Ottawa explains timing. Support hardware can be installed in any season, though a tree in winter is easier to read because you can see the full branch structure.
A supported tree is a managed tree, not a fixed one. The cable does not stop the tree from changing: it keeps growing, the hardware has to be checked as it does, and the weak fork can still deteriorate. Plan on having it inspected on a regular schedule, and after any major storm. Anything that has loosened, frayed or been outgrown needs to be adjusted or replaced.
Do not improvise with rope, chain or wire wrapped around a limb. That kind of tie cuts into the bark as the branch thickens, girdles it, and can kill the very limb you were trying to hold. Support hardware is installed through or between branches in a way that does not strangle them, and the work is done high in the tree with proper rigging. It is not a ladder job for the weekend.
Under Ottawa's Tree Protection By-law, work that maintains a tree's health and follows good arboricultural practice does not need a permit, but heavy cuts or damage can still count as injuring a protected tree. A tree on the City boulevard belongs to the City: call 3-1-1 rather than working on it yourself.
Bisson Services handles tree pruning, including cabling and bracing, across Ottawa and Prescott-Russell. Call (613) 558-4806 for a free estimate. After a look at the tree, we can tell you whether support, pruning or removal makes sense.
A cable is a flexible line installed high in the crown to limit how far limbs can spread. A brace is a threaded steel rod passed through a trunk or limb to hold a crack or tight fork together. They are often used together.
Done properly, no. Modern systems are installed to allow natural movement and do not wrap the limb. Improvised rope, chain or wire does harm, because it girdles the branch as it grows.
Yes. Support lowers the risk of a weak union splitting, but it does not repair decay, fix failing roots or make a tree storm-proof. That is why supported trees need regular inspection.
Trees with a structural defect, such as a tight V-shaped fork with included bark, or a crack in a main stem, that are otherwise healthy. A tree with hollow wood, a new lean or a dying crown is not a candidate.
Work that maintains a tree's health and follows good arboricultural practice does not need a permit under the Tree Protection By-law. A tree on the City boulevard belongs to the City, so call 3-1-1.
Free on-site estimates, bilingual service, 24-hour emergency response. Bisson aims to reply the same day.
