The short answer
Prune apple trees in winter, between November and early March, when the tree is dormant and bare. Remove no more than about a fifth of the branch framework in any one year. Thin out crowded, crossing and dead wood to open the centre, rather than shortening every shoot. Little and often, every winter, gives a healthier tree and steadier crops than one heavy cut every few years.
Why prune an apple tree?
An unpruned apple tree is not a dead tree. It will keep fruiting. But over time the crown becomes congested, fruit gets smaller and higher up, and damp, still air inside the canopy encourages scab and canker. In the west of Scotland, where summers are wet and humid, good airflow matters more than in drier parts of the UK.
Pruning aims to:
• keep a steady supply of young fruiting wood, which crops best when it is between one and four years old
• let light into the middle of the tree so fruit ripens and colours
• improve airflow to reduce fungal disease
• keep the tree to a size you can pick from safely
When to prune apple trees
Winter (November to early March) is the main pruning season for free-standing bush and standard trees. With the leaves gone, you can see the structure clearly. Avoid hard frost, when wood is brittle.
Summer (mid to late August) is for trained forms such as cordons, espaliers and step-overs. Summer pruning keeps them tight and encourages fruit buds. It also checks vigour, so it can help with an over-vigorous bush tree.
Know your tree: spur or tip bearer?
Before you cut, check where your tree carries its fruit.
• Spur bearers carry most of their fruit on short, knobbly side shoots along the older branches. Most apple varieties are spur bearers. They respond well to regular winter pruning.
• Tip bearers fruit mainly at the ends of the previous year’s shoots. If you shorten every shoot, you cut off next year’s crop. ‘Bramley’s Seedling’ and ‘Discovery’ are among those that fruit partly at the tips.
On tip and partial tip bearers, thin out whole branches instead of shortening shoots.
How to prune an apple tree, step by step
1. Stand back and look first. Walk round the tree and decide what needs to go before you make a cut. Real trees rarely look like the diagrams.
2. Take out the dead, damaged and diseased wood back to healthy growth.
3. Remove crossing and rubbing branches. Keep the better placed one.
4. Open the centre. Remove branches growing into the middle of the tree to create a goblet shape with space for light and air.
5. Thin, don’t trim. Spread your cuts through the whole canopy. Cutting only the outer shoots, as you would a hedge, leads to a mass of leafy, unfruitful growth and removes fruiting wood.
6. Replace some old wood. Cut out a few of the oldest, least productive side branches each year to make room for younger ones.
7. Stop at around 20%. If the heap of prunings is getting large, leave the rest for next winter.
Making good cuts
• Use clean, sharp secateurs for small shoots, loppers for medium branches and a pruning saw for anything thicker.
• The bulk of your work should be on branches between thumb and broom-handle thickness.
• Avoid removing very large limbs. Big wounds are slow to close and invite decay. If a large branch must go, cut it back to a fork or side branch rather than leaving a bare stub.
• Skip the wound sealant. Apple trees seal their own cuts.
• Use a stable tripod ladder for anything above head height.
Dealing with watershoots
Hard pruning makes a healthy tree push out strong, upright shoots known as watershoots. Remove most of them at their base in winter, or pull them off while young and soft in summer. Where one sits in a gap you want filled, keep it and take off roughly a third of its length so it branches out.
Renovating an old or neglected apple tree
Do not try to fix a neglected tree in one winter. Spread the work over three years or more, removing no more than about 20% each year. Start with dead and diseased wood, then crossing branches, then gradually lower the height and open the centre. Heavy pruning in a single season gives you a thicket of watershoots and very little fruit.
Common problems you may notice while pruning
• Lichen and moss on bark are harmless and very common in Scotland’s damp air. No action needed.
• Apple canker shows as sunken, cracked, flaking areas of bark, often around a bud or wound. Prune back infected shoots and smaller branches to clean wood. Canker is worse on wet, poorly drained soils.
• Brown rot leaves shrivelled, mummified fruit hanging on the tree. Remove and dispose of it.
• Dead branches with no obvious cause may point to a root problem. If dieback keeps spreading, get advice from an arborist.
• Cavities in old trunks are usually nothing to worry about, and drilling drainage holes does more harm than good. Ask an arborist to look if a hollow is getting bigger or fungal brackets develop.
Frequently asked questions
When is the best time to prune an apple tree in Scotland?
November to early March, while the tree is dormant. Avoid periods of hard frost. Trained forms such as espaliers and cordons are pruned in late summer.
How much can I cut off an apple tree?
No more than about a fifth of the canopy in one winter. Heavier pruning triggers vigorous, unfruitful regrowth.
Can you prune an apple tree in summer?
Yes, for trained forms, and to slow down an over-vigorous tree. Summer pruning reduces growth, while winter pruning stimulates it.
Why is my apple tree not fruiting after pruning?
The most likely causes are cutting too hard, which pushes the tree into leafy growth, or shortening every shoot on a tip-bearing variety, which removes the fruit buds.
Do I need to seal pruning cuts on apple trees?
No. Apples close their own wounds without any sealant.
How do I prune an overgrown apple tree?
Gradually, over at least three winters, taking out no more than about 20% each year.
Need help with fruit trees in Scotland?
I am a Chartered Horticulturist and Master of Horticulture (RHS) with over 20 years’ experience. Tom Angel Studio provides an apple tree pruning service (and other fruit trees as well) all across Glasgow.
If you are looking for tree planting advice in Glasgow, Edinburgh or anywhere across the central belt, give Tom a call on 0141 432 1141 or email on tom@tomangel.co.uk