Blossom end rot

A sunken, leathery black patch on the blossom (bottom) end of the fruit. It is not a disease or pest but a calcium-uptake problem, usually triggered by uneven watering rather than a lack of calcium in the soil.

Dark, flattened, sunken area at the base of the fruit that enlarges as the fruit grows. The rest of the plant looks healthy.

Remove affected fruit so the plant redirects energy. There is no spray cure, the fix is even moisture (see prevention).

Water deeply and consistently, mulch to buffer soil moisture, and avoid heavy nitrogen feeds during fruiting. Most later fruit sets cleanly once watering steadies.