Why winter is the right time to prune

An apple tree in full leaf is busy. Sap is moving, fruit is swelling, and every cut you make is a wound the tree has to seal while also feeding a crop. Wait until it is dormant — roughly November through to early March — and the same cut costs the tree far less. It has energy stored in its roots and trunk, it is not pushing growth, and it can close the wound cleanly before spring.

There are exceptions worth knowing. If your tree is a trained form — a cordon, espalier or fan — you will be doing some pruning in late summer instead, because you want to encourage fruit spurs rather than leafy growth. And if you garden in the colder parts of the UK, in northern England or the Scottish Borders, aim for late February to early March rather than midwinter, so the cut surfaces are not exposed to hard frost for months on end. Avoid pruning on a day when the wood is frozen solid; it shatters rather than cuts.

Before you cut anything, stand back and look

The single most useful thing you can do is spend five minutes walking around the tree before you touch it. Apples fruit best on a framework that is open in the middle, like a wine glass or a goblet. Light and air moving through the centre means better ripening, fewer fungal problems, and easier picking.

What you are looking for is a clear picture of the permanent branches — usually five to seven of them, radiating outwards and upwards from the trunk, well spaced. Anything that competes with that picture is a candidate for removal. Once you can see that shape in your head, the pruning itself becomes almost obvious.

The three Ds, and the branches that rub

Start with the wood that has to go, whatever the tree's overall shape. Work through this list first:

• Dead wood — brittle, grey-brown, snaps easily, no green under the bark.
• Diseased wood — canker shows as sunken, cracked patches with a rusty ring; cut back to clean, healthy wood.
• Damaged wood — split or broken branches, often the result of wind or a heavy crop.
• Crossing branches — where two limbs rub, the bark wears away and infection gets in.
• Branches growing inwards — anything heading back towards the centre of the tree.
• Vigorous upright shoots — the strong, straight growths that shoot up from a branch. Take them out unless you need one to fill a gap.

Crossing branches are the ones people miss most often. Run your hand along the framework and feel for contact points. If two branches touch, one of them goes — usually the weaker, or the one growing in the wrong direction. Take the whole branch back to its point of origin rather than leaving a stub.

How to make a cut the tree can heal

A good pruning cut is made just outside the branch collar — the slightly swollen ring of tissue where the branch meets the trunk or parent limb. Cutting flush against the trunk removes the collar and leaves a big wound that heals badly. Leaving a long stub is just as bad: the wood dies back and invites disease.

On anything thicker than a finger, use the three-cut method. First, make a small cut underneath the branch about 30cm from the trunk. Second, cut down from above, a little further out, so the branch falls away cleanly without tearing bark. Third, remove the stub with a final cut just outside the collar. Use sharp bypass secateurs for thin growth, loppers for the middle wood, and a pruning saw for anything substantial. Bypass tools cut cleanly; anvil types crush the wood.

Angle your cut slightly away from the bud or branch you are cutting back to, about 45 degrees, so water runs off rather than sitting on the wound. There is no need to paint wounds with sealant — modern advice is to leave them open to the air.

Young trees, old trees and neglected trees

A young tree needs shaping, not a heavy haircut. Choose your main framework branches over the first few winters and shorten the leaders by about a quarter to encourage branching, always cutting to an outward-facing bud. The aim is a strong, well-spaced structure that will carry fruit for decades.

An established, well-pruned tree needs very little each year — thin out crowded growth, remove the three Ds, and shorten a few of last year's shoots on the outer branches. A neglected tree is a different job. Do not try to fix it in one winter. Take out the dead, diseased and crossing wood first, then spend the next two or three winters thinning the centre. Removing more than about a quarter of the canopy at once invites a thicket of vigorous regrowth and sets you back.

Remember that some varieties fruit on the tips of last year's growth rather than on spurs — many of the older culinary sorts behave this way. If in doubt, prune lightly and watch where the fruit forms next summer.

After the job is done

Clear up all prunings from around the base of the tree. Diseased wood should be burned or taken to the tip; clean wood can be chipped and composted, or bundled into a corner as a habitat pile for beetles, hedgehogs and solitary bees. That is a small wildlife win from a morning's work.

Give the tree a mulch of well-rotted compost or manure around the root area, keeping it clear of the trunk itself. If you pruned hard, expect a flush of new shoots next summer — thin these in July rather than leaving them to crowd the centre. Above all, keep the cut surfaces clean and your tools sharp, and your apple tree will reward you with an open, airy crown and a heavier, healthier crop for years to come.