Here are tips on how to identify, control, and prevent blossom-end rot on your tomatoes and other garden plants.
What is Blossom-End Rot?
Why are your tomatoes rotting on the bottom? Unfortunately, they probably have blossom-end rot. It is a common problem on tomatoes, peppers, eggplants, and squash caused by a low concentration of calcium in the fruit. (Calcium is needed for normal cell growth.) Blossom-end rot usually occurs when there are wide fluctuations of moisture, which reduces uptake and movement of calcium into the plant. When the demand for calcium exceeds the supply, the tissues break down.
Calcium deficiency during fruit formation can also be caused by too much nitrogen fertilizer, high salt levels in the soil, or damage to plant roots during cultivation. Be aware of these causes when caring for tomatoes in order to prevent blossom-end rot.
Some blossom-end rot is more or less normal in the first tomatoes of the season, since the plants are usually under stress during the initial fruit set. If the damaged portion is small, you can trim it off and enjoy the rest of the tomato. Hopefully the problem will ease, because after all, no one wants rotten tomatoes!