How and When Should I Thin Apricot Fruits?

Apricot thinning — deliberately removing some of the developing fruitlets in late spring — is one of the most effective management practices available to the home grower. Thinned fruit is larger, sweeter, and more evenly ripened than unthinned fruit from the same tree, and thinning prevents the weight of a heavy crop from breaking branches. In a season when the tree has set heavily — which is uncommon in the UK due to frost risk but does occasionally happen — thinning is essential.

When to thin

Thin apricots after the natural fruit drop is complete — usually late May to mid-June. This natural drop sheds the smallest and most poorly-developed fruitlets first. Wait for it to finish before thinning so you are not removing fruit the tree would have shed naturally anyway. Thinning too early can also be undone if more natural drop occurs afterward. By mid-June, the remaining fruitlets should be reasonably stable and thinning can proceed.

Target spacing

Thin to one fruit every 7–8 cm along the branch. In practice this usually means removing all but one fruitlet from each spur cluster, then checking that the remaining individual fruits are adequately spaced. The goal is that no two fruits are touching or very close to touching once they reach maturity — touching fruit transfers brown rot from fruit to fruit and results in adjacent fruits rubbing and scarring each other's skin.

Which fruitlets to remove

Remove the smallest fruitlets from each cluster first, then remove any with visible damage, deformity, or pest entry holes. Keep the largest, most symmetrical fruitlet from each cluster in the most well-lit position. Use scissors or a clean snip of the fingers — never pull, as this risks damaging the spur.

Benefits beyond fruit size

A heavily laden branch can break under the weight of a full crop, permanently damaging the tree's framework. Thinning to a manageable crop load protects the structural integrity of the branches, particularly the more slender laterals on a wall-trained fan.