Which one fixes my problem?
| What happens | Good for | |
|---|---|---|
| Crown thinning | Selected branches come out through the crown (the leafy top) so it's less dense but keeps its shape | More light and air under the tree, and less wind caught in the crown |
| Crown lifting | The lowest branches come off to raise the bottom of the crown | Clearance over a driveway, path, roof or lawn |
| Crown reduction | Branches are shortened back to smaller side branches, so the crown is smaller but still natural | A tree that's outgrown its spot, or long limbs over the house |
| Deadwooding | Dead branches still on the tree are cut out | Stopping dead limbs dropping on people, cars or the roof |
How is reduction different from lopping?
Both make a tree smaller, but the cuts land in different places. Reduction cuts back to a living side branch that can take over. Lopping cuts between growing points and leaves a stub, which Whitehorse City Council says usually brings bushy growth that's often poorly attached. AS 4373 lists lopping and topping as unacceptable. Our lopping vs pruning guide explains why.
What should a pruning quote say?
Numbers, not just words. Newcastle's tree manual says a crown thinning specification must state the total percentage of crown removed and the largest branch size, and a crown lifting one the clearances to be reached. That's a sound model anywhere.
Balance matters too. A report on Cyclone Yasi found that pruning one side of a canopy for power line clearance creates crown asymmetry, which can increase twisting damage to trunks in cyclones. Ask how the crown will be kept even.
Questions to ask before saying yes
- Will the work follow AS 4373?
- What percentage of the crown will come off, and what's the largest branch you'll cut?
- For lifting, what clearance will we end up with?
- Will any cut leave a stub?
- Does this tree need council approval to prune, and who applies?
- Who will make the cuts, and do they hold the Certificate III in Arboriculture?
Can pruning need council approval?
Yes. In the ACT, major pruning of a protected tree, meaning removing branches greater than 100 mm in diameter, needs approval. Inner West Council in Sydney requires a permit for pruning more than 10% of a prescribed tree's canopy. In South Australia, excessive pruning of a regulated tree can count as tree-damaging activity, and the City of Onkaparinga says approved pruning should be no more than 30% of the crown every 5 years. Clear a big reduction with the council first: see tree removal permits.
Is a branch near a power line?
Crown lifting over a driveway often brings branches near the line to the house. Leave those alone. SafeWork NSW says that if any part of a branch touches an electric line, the whole branch, leaves included, may be live. In Victoria, Energy Safe Victoria says a tree near your own service line is yours to clear, and advises getting a qualified professional to do it. Our power lines guide shows which network to call.
Tree pruning: what you can do yourself
You can
- Small dead twigs and low branches you can reach from the ground, with loppers or a pruning saw.
- Measuring the clearance you actually need over the drive or path.
- Photographing the tree from a few sides for the arborist and the council.
Leave to an arborist
- Thinning and reduction, which need judgement right through the crown.
- Anything above head height, and large lower limbs on a crown lift.
- Any branch near a power line.
Hiring an arborist for tree pruning
We'd describe the problem, not the cut, and ask for the answer in numbers: how much of the crown, the biggest cut, and the clearance at the end. A plan that's only a height to take off the top, with nothing about where the cuts go, is lopping by another name.