7 minute read -
Pruning Trees: The Right Time, the Right Cut and the Right Tools
Most deciduous trees are best pruned in late winter, while they are dormant and it is not freezing, or in summer for small corrections. Trees that bleed sap, such as maple, birch and walnut, are pruned in summer or early autumn, and stone fruit like cherry and plum after harvest.
When pruning trees, cut just outside the branch collar, remove no more than about a quarter of the crown in a year and leave high or heavy limbs to a tree surgeon.
What will you learn in this article?
- Why prune a tree?
- When is the best time to prune trees?
- What tools do you need to prune trees?
- How to prune a tree, step by step
- Pruning large and small trees: what is the difference?
- How to prune tall trees safely
- Which pruning mistakes should you avoid?
- Frequently asked questions about pruning trees
- In short: pruning trees
Why prune a tree?
Pruning has several purposes:
- Safety: dead, broken or heavy branches can fall onto a path, patio, car or roof.
- Health: removing diseased or damaged wood stops problems from spreading.
- Shape and light: a thinned crown lets in light and air, which gives fungal disease less chance.
- Directing growth: formative pruning on young trees decides how the crown develops.
- Fruiting: on fruit trees, good pruning gives more and better fruit.
When is the best time to prune trees?
The right moment depends on the species, so look up your tree if you are unsure. Use this table as a guide:
| Type of tree | Best time | Why |
|---|---|---|
| Most deciduous trees | Late winter (frost-free) or summer | Little stress when dormant; wounds close faster in summer |
| Maple, birch, walnut | Summer to early autumn | They bleed heavily if cut in late winter or spring |
| Cherry, plum, peach (stone fruit) | Summer, after harvest | Lower risk of infections such as silver leaf |
| Apple and pear | Winter (formative) and summer (maintenance) | Winter builds the framework, summer slows growth |
| Pollarded trees (such as willow) | Winter, while dormant | The tree regrows vigorously in spring |
| Espaliers and pleached trees | Winter for structure, summer to tidy | Keeps the flat shape crisp |
| Conifers | Lightly during the growing season | Many species will not regrow from old wood |
Do not prune in hard frost. Frozen wood is brittle and the wound can tear. For conifers, see our guide to pruning conifers.
Summer or winter pruning?
Winter pruning triggers strong growth in spring, which is useful when you want to build up or renew a tree. Summer pruning slows growth a little and wounds close faster. For small corrections, such as removing water shoots and awkward branches, summer is often the best time. Do watch out for nesting birds.
Can you prune during the nesting season?
It is an offence to damage or disturb an active nest at any time of year, and most birds nest between roughly March and August. Check the tree before you start. If there is an active nest, wait until the young have fledged.
What tools do you need to prune trees?
| Tool | Suitable for |
|---|---|
| Secateurs | Thin twigs, up to about thumb thickness |
| Loppers (long handles) | Slightly thicker branches, with more leverage |
| Pruning saw | Branches too thick for loppers |
| Pole pruner or telescopic saw | Higher branches from the ground |
| Chainsaw | Thick branches you can reach from the ground, and trunks |
Choose bypass secateurs with two cutting blades where you can. They cut cleanly and crush less than anvil secateurs. For thick branches, a cordless chainsaw from the Maxxpack 18V range is a handy option: no cable, no fumes and ready to go straight away. Check the guide bar length in its specifications to see the maximum branch thickness it can handle.
Keep your tools sharp and clean. A clean cut heals better than a ragged one. Clean your tools after pruning a diseased tree so you do not carry the problem to the next one.
How to prune a tree, step by step
Look at the tree
Walk round the tree and decide what needs to go. Start with dead, broken and diseased wood. Then look at branches that cross or rub, grow inwards or are too crowded.
Decide how much to remove
Take off no more than about a quarter of the crown per year. Over-pruning weakens the tree and triggers a mass of water shoots. If a tree has been neglected for years, spread the work over several seasons.
Make the cut in the right place
Cut just outside the branch collar, the slightly swollen ring where a branch grows from the trunk or a larger limb. Do not cut flush with the trunk, as this damages the tissue that seals the wound. Do not leave a long stub either, because it dies back and can rot.
When shortening a branch, cut just above a bud or side shoot that points in the direction you want. That is where the new growth will go.
Cut thick branches in three stages
A heavy branch often tears bark from the trunk as it falls. Prevent this as follows:
- Undercut: some distance from the trunk, saw partway up into the underside of the branch.
- Top cut: a little further out, saw down from above. The branch breaks off without tearing.
- Final cut: trim the remaining stub neatly just outside the branch collar.
Clear up and check
Clear away the prunings and check after a few weeks that the tree is responding well. Wound paint is usually unnecessary, as the tree seals the wound itself.
Pruning large and small trees: what is the difference?
Young and small trees are mainly pruned for shape. Choose a clear central stem (the leader) and a few well-spaced main branches. Do a little every year so you never have to remove thick branches later.
Large trees mostly need maintenance: removing dead wood, thinning the crown and, if needed, crown lifting, where you remove the lowest branches for more headroom. Big limbs on a mature tree are heavy and unpredictable.
How to prune tall trees safely
Work from the ground as much as possible with a pole pruner or telescopic saw. Never use a chainsaw on a ladder: if the saw kicks back or the branch twists, you cannot step away. Wear a helmet, safety glasses and gloves, and with a chainsaw also chainsaw trousers and chainsaw boots. Never stand under a branch you are cutting and keep others well away.
Before major work, also check with your local council that the tree is not covered by a Tree Preservation Order or in a conservation area.
Which pruning mistakes should you avoid?
- Topping or lopping: cutting off the top or all the main limbs at the same height. This produces lots of weak, poorly attached shoots and an unstable tree.
- Too much at once: removing more than a quarter of the crown.
- Pruning in frost, or pruning bleeders in spring.
- Leaving stubs, or cutting too close to the trunk.
- Ignoring water shoots: the straight, fast-growing shoots on the trunk and branches waste the tree's energy. Remove them, ideally in summer.
Frequently asked questions about pruning trees
How often should I prune a tree?
Most garden trees need only a light prune every year or two. Young trees and fruit trees benefit from some attention every year. Pollarded trees are usually cut back every few years.
Can I prune a tree in any season?
Light work, such as removing a broken branch, can be done at any time. For bigger jobs, stick to the right time for the species, avoid frost and keep nesting birds in mind.
Should I fell a tree with lots of dead branches?
Not necessarily. A good prune often keeps a tree going for years. If there are many dead branches, fungi at the base or cavities in the trunk, ask a tree surgeon to check whether the tree is still safe.
Is a cordless chainsaw powerful enough for pruning?
For branches and thin trunks you can reach safely from the ground, a cordless chainsaw works well. Pay attention to the guide bar length and keep the chain sharp. Leave thick branches high in the tree to a professional.
In short: pruning trees
Prune most trees in late winter or summer, bleeders like maple and birch in summer, and stone fruit after harvest. Cut just outside the branch collar, take off no more than a quarter of the crown each year and use the three-cut method on heavy branches. Anything high, heavy or near cables is a job for a tree surgeon.
