Why apples rot before ripening — and how to save this year's harvest

In midsummer, apple trees often look promising, their branches bending under beautiful, juicy fruit. Yet sometimes it takes just one day for a crisp, fragrant apple to turn soft and covered in brown spots.

According to horticultural experts, the cause is often a tiny microcrack in the apple's skin, left by an insect bite or a bird's peck. Fungi easily enter through such damage, sometimes barely visible, and begin destroying the fruit from the inside, even while the apple still looks healthy from the outside.

Brown rot — a serious threat

One of the most dangerous apple tree diseases is brown rot, which can destroy entire trees and significantly reduce yields. In its early stages, the disease may show only small, almost unnoticeable spots on the fruit's surface. The fungus gradually spreads inside the apple, and over time the spots grow larger as the fruit softens and begins to rot.

Brown rot spreads quickly, since infected fruit can easily pass the fungus on to neighboring apples. As a result, damage can affect not just individual fruits but an entire branch or even several branches at once. Warm, humid weather especially encourages the disease's development, making it a serious threat to the summer and autumn harvest.

How to protect the harvest

Gardeners are advised to regularly check fruit and promptly remove already damaged apples before they infect the rest. It also helps to thin out the tree's crown by removing overly dense branches, improving air circulation. Early prevention is essential, since brown rot can spread from just a few fruits to an entire tree or even several trees in the garden.