How do I thin apples, pears and plums, and how much should I take off?

A fruit tree sets far more fruit than it can fill, then sheds some of it in the June drop, then still carries more than it can fill. The consequences of leaving it are all bad: small watery fruit, branches breaking under the weight, and — worst of the three — so much energy going into seed that the tree fails to lay down fruit buds for next year and drops into cropping every other year.

What you'll need

• Sharp scissors or snips
• A bucket for the thinnings
• Something to stand on for the higher branches (optional)

Step by step

1. Wait until the June drop has finished.Usually mid to late June in the south, into early July further north. The tree sheds what it cannot carry first; thinning before that means doing the job twice and possibly over-thinning.
2. Work cluster by cluster rather than branch by branch.Each flower cluster typically sets four to six fruitlets. Reduce each one to one fruit, or two where the branch is strong and the crop is light.
3. Take the damaged fruit first.Anything scarred, misshapen, russeted on a smooth variety, or with a small hole and frass at the eye — that last one is codling moth, and removing it takes a caterpillar out of next year's population too.
4. Decide about the king fruit.The king is the central fruit that set first and is usually the biggest, so on apples it is normally the one to keep. If it is lumpy or distorted, which happens quite often, keep the best of the others instead.
5. Space what is left along the branch.Dessert apples 10–15cm apart, cooking apples 15–20cm, pears left in pairs with 10–15cm between pairs, plums and gages 5–8cm. Measure the first few with your hand and then work by eye.
6. Snip rather than pull.Cut the stalk with scissors, taking the stalk away with the fruit. Pulling risks tearing off the whole spur, which removes fruit buds for future years as well.
7. Thin a young tree much harder.A tree in its first two cropping years should carry very little — a handful of fruit at most. Letting a young tree crop heavily stunts it permanently and can pull the leader out of shape.
8. Prop or tie any branch still carrying a heavy load.Plums in particular break under their own crop, and a torn plum branch is an open wound in the season when silver leaf spores are about. A forked stick or a padded rope tie from the trunk saves the branch.
9. Clear up the thinnings.Rake up and remove the fallen and thinned fruit, especially anything grubby or rotting, rather than leaving it under the tree where it carries pests and brown rot into next season.

Tips

• Thinning is the practical cure for biennial bearing. Thin hard in the heavy year and the tree lays down buds for the light year.
• Pears need less thinning than apples and are usually left in twos, because pear fruitlets are naturally better spaced.
• Cherries are not thinned. Nor are most soft fruits.
• If a branch is bending noticeably by mid-July, you did not thin enough. Take more off now rather than losing the branch.
• Thinning also improves airflow around each fruit, which reduces brown rot and stops one rotting fruit infecting the one it is touching.

Common mistakes

• Not thinning at all because it feels wasteful — You get the same total weight in far smaller fruit, a broken branch or two, and probably no crop at all next year. The tree wastes it either way; thinning decides where the energy goes.
• Thinning before the June drop — The tree is about to shed a proportion of the crop itself. Thin first and you can end up with almost nothing.
• Pulling fruitlets off by hand — It tears the spur, which is a permanent fruiting point that would have cropped for many years. Snip the stalk instead.
• Letting a two-year-old tree carry a full crop — It checks growth badly at the stage when the framework is being built, and the tree spends years catching up.

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