6 minute read -
Pruning Thick Branches: How to Cut Them Safely Without Tearing
You do not cut thick branches with secateurs, you saw them. Loppers handle branches up to about the thickness of your thumb; above that, use a pruning saw or, for lots of heavy branches, a chainsaw. Remove a thick branch in three cuts so the bark does not tear, and leave the swelling where the branch meets the trunk (the branch collar) intact.
Follow that method and pruning thick branches leaves a clean wound the tree can seal itself, without long strips of torn bark down the trunk.
What will you learn in this article?
- Which tool suits which branch thickness?
- How do you cut off a thick branch without tearing the bark?
- When should you prune thick branches?
- Should you seal a pruning wound?
- How do you prune thick branches at height?
- Do you need permission?
- How do you keep pruning tools sharp and clean?
- Pruning safely
- Frequently asked questions about pruning thick branches
- In short: pruning thick branches
Which tool suits which branch thickness?
| Tool | Suitable for | Watch out for |
|---|---|---|
| Secateurs | Thin twigs and young shoots | On thicker branches you crush the wood and strain your wrist |
| Loppers | Branches just too thick for secateurs | Long handles give more leverage, but very thick wood is beyond them |
| Hand pruning saw | Thick branches from hand to shoulder height | Small, often folding, controlled and precise |
| Pole saw or telescopic pruning saw | Branches high in the tree, from the ground | Never stand under the branch you are cutting |
| Chainsaw | Lots of thick branches, heavy limbs and trunk wood | Only with full protective clothing |
The maximum cutting diameter varies between loppers and is listed in the specifications. If you have to force or twist the tool, the branch is too thick for it.
Why a pruning saw is better than loppers
Loppers that are overloaded crush and split the wood. A ragged wound like that heals poorly and lets fungi in. A pruning saw makes a clean, smooth cut. Pruning saws often have a curved blade with coarse teeth that clear fresh, wet wood well without binding.
Pruning with a cordless chainsaw
For lots of thick branches, or clearing up a tree that has come down, a chainsaw is the quickest tool. A cordless chainsaw, for example from the Maxxpack 18V range, is quieter than a petrol model and starts straight away. Never use a chainsaw above shoulder height, never from a ladder and never one-handed. For work high in the tree, a pole saw is the safer choice.
How do you cut off a thick branch without tearing the bark?
If you saw through a heavy branch in one go, it snaps partway through and strips a length of bark down the trunk with it. Work in three cuts instead:
- Undercut: about a hand's width to a foot from the trunk, saw upwards into the underside of the branch to about a third of its thickness.
- Top cut: a little further out from the trunk, saw down through the branch from above. The branch breaks off between the two cuts and the bark does not tear any further.
- Remove the stub: cut the remaining stub off neatly, just outside the branch collar.
Where is the branch collar?
The branch collar is the swollen ring or ridge where the branch grows out of the trunk. This is the zone where the tree seals off the wound. Do not cut flush against the trunk, as you will damage the collar and make the wound larger. Do not leave a long stub either, because it dies back and rots.
When should you prune thick branches?
For most deciduous trees and shrubs, late winter or early spring is a good time, as long as there is no hard frost. Trees that bleed heavily, such as birch, maple and walnut, are better pruned in summer or late summer when the sap flow is lower. Fruit trees often have their own pruning times. Avoid removing heavy branches during hot, dry spells or just before a hard frost.
Can you prune during the nesting season?
You can prune, but in the UK it is an offence to damage or destroy an active bird's nest. The main nesting season runs roughly from March to August. Check the tree or shrub for nests before you start, and put off heavy pruning if there is an active nest.
Should you seal a pruning wound?
Usually not. A healthy tree seals a well-made cut itself, starting from the branch collar. A wound sealant can trap moisture beneath it. What matters more is a smooth cut in the right place, made with a sharp tool.
How do you prune thick branches at height?
Ideally use a pole saw or telescopic pruning saw so you can work from the ground. Stand to one side of the branch, never underneath it, and think about where it will fall. Keep people out of the area below. If you do have to use a ladder, set it up firmly, have someone foot it and never use a chainsaw from a ladder.
Leave heavy branches over a roof, shed or cables, and anything you cannot reach safely from the ground, to a qualified tree surgeon.
Do you need permission?
For ordinary pruning, usually not. However, if the tree is covered by a Tree Preservation Order or stands in a conservation area, you may need consent from your local council before you prune it, even for smaller work. Hard cutting back or removing large main limbs can also count as significant work. Check with your local council before you start.
How do you keep pruning tools sharp and clean?
Blunt tools take more effort, strain your joints and leave ragged wounds. Sharpen secateurs and loppers with a sharpening stone, and replace a blunt saw blade or sharpen the chain on your chainsaw. Clean sap and resin off blades after use, and disinfect them when you move from a diseased tree to a healthy one. A lightly oiled blade will not rust.
Pruning safely
- Wear work gloves and safety glasses.
- With a chainsaw: chainsaw trousers, safety boots, a helmet with a visor and ear defenders.
- Work in pairs on heavy branches and make sure nobody is in the drop zone.
- Keep well away from overhead power lines. If a branch is near one, contact your electricity network operator rather than cutting it yourself.
- Remove the battery from the chainsaw before you check or tension the chain.
Frequently asked questions about pruning thick branches
Why does the bark tear when I saw off a thick branch?
The branch breaks under its own weight before you have finished the cut. An undercut followed by a top cut prevents this, and you then cut the stub off neatly.
Can I cut thick branches with loppers?
Only if they are within the maximum cutting diameter of the loppers. If you need to twist or squeeze hard, use a pruning saw.
How thick a branch can a pole saw cut?
That depends on the length of the blade or guide bar, so check the specifications of the saw. Very thick branches high in a tree are best left to a tree surgeon.
Is a cordless chainsaw powerful enough for pruning?
For most branches in an ordinary garden, yes. It depends on the bar length and the battery, so check the specifications to see what branch thickness the saw can handle.
In short: pruning thick branches
Choose your tool by branch thickness: secateurs or loppers for thin wood, a pruning saw for thick branches and a chainsaw for lots of heavy work. Cut thick branches off in three stages, just outside the branch collar. Prune at a suitable time, check for nests and leave heavy branches at height to a professional.
