Why pears reward careful pruning

Pear trees are a good-natured lot, but left entirely to their own devices they grow tall, upright and congested. Unlike apples, which often spread outwards naturally, a pear pushes its branches upwards, producing a dense head that shuts light out of the centre. The result is fruit that ripens poorly in the shade and spurs that gradually lose vigour.

Pears crop mainly on short fruiting spurs carried on wood two years and older. Those spurs cluster tightly, and if you never thin them you end up with a mass of small, hard pears rather than the fat, well-coloured fruit you were hoping for. Add the fact that pear wood is more brittle than apple wood and can snap under a heavy crop, and the case for shaping your tree properly makes itself.

When to prune: winter for structure, summer for control

Timing matters more with pears than with almost any other fruit tree in the UK garden, and the reason is silver leaf. The fungus that causes it releases spores most freely in autumn and early winter, and pruning wounds made in mild, damp weather are a perfect doorway for infection. So the old advice to prune in November is best forgotten.

Work with two windows instead:

• Late winter (January to February) — the main season for structural work. The tree is dormant, the sap is not rising, and wounds begin sealing as growth starts in spring. This is the time to remove whole branches, reshape the framework and open up the centre.
• Late summer (late July to August) — the moment for trained forms such as espaliers, fans and cordons, and for taming a tree that grows too vigorously. Pruning in summer checks growth rather than stimulating it, and dry weather means far less risk of disease entering the cuts.

Avoid September, October and November unless you really must cut — that is prime silver leaf weather. Never prune when the wood is frozen solid, as the tissues below the cut can be badly damaged.

Tools and clean cuts

Use bypass secateurs for anything up to a finger's thickness, loppers for branches up to about 2.5cm, and a pruning saw beyond that. Keep the blades sharp: a ragged cut heals slowly and invites canker. Wipe them with methylated spirits between trees, particularly if you know one of them has disease.

Make cuts just above a bud or a pair of buds, sloping away from the bud so rainwater does not sit on it. Do not leave long stubs — they die back and rot — but do not cut so tight that you nick the bud either. On branches thicker than your wrist, use the three-cut method: a notch underneath, a cut from above a short way out along the branch, then a final tidy cut back to the branch collar.

Pruning a young pear tree: the first four years

For a maiden whip planted in the open, aim for an open-centred bush. In the first winter, shorten the main stem to around 60–75cm above ground, cutting to a bud, to encourage side shoots. The following winter, choose three or four well-spaced shoots pointing in different directions to form the framework, and shorten each by about a third. In later winters, keep the centre open, shorten the leaders by a quarter to a third, and rub out or cut away anything crossing or crowding.

Trained trees need the same patience but a different schedule — tie in new growth and shorten it in late summer, which keeps the shape neat and encourages fruiting spurs along the arms. Cordons are usually pruned this way from the start, cutting the new shoot back to three or four leaves above the basal cluster.

Pruning an established pear tree

Once the frame is set, pruning becomes annual housekeeping rather than surgery. Work through the tree in this order:

• Remove dead, damaged and diseased wood, plus any branches rubbing against each other.
• Cut out water shoots — those vigorous vertical stems that bolt up from the branches — unless you need one to fill a gap.
• Thin congested spurs every three or four years, spacing them roughly 10–15cm apart along the branch.
• Shorten the previous season's growth on main branches by about a quarter, cutting to a good outward-facing bud.

The test is simple: in summer you should be able to throw a hat through the middle of the tree. If you cannot, it is too crowded, and fruit quality will suffer accordingly.

Aftercare and what to watch for

Feed in late winter with a balanced general fertiliser and mulch around — but not against — the trunk, then thin the developing fruitlets in June and July if the crop is heavy, leaving one or two per cluster. Watch for silver leaf, where the leaves take on a pearly sheen and the wood stains brown inside when you cut across it, and for canker, which shows as sunken, cracked bark. Cut either out promptly in late summer, and clean your tools afterwards.

Prune patiently, at the right time of year, and a well-shaped pear tree will keep cropping generously for decades.