Symptom : it’s a common problem with homegrown tomatoes. It initially appears as a depressed, leathery, brownish area the size of a dime to a half dollar on the blossom end of the fruit.
Cause : It is caused by a calcium deficiency coupled with wide fluctuations in available moisture. Training and pruning the tomato vines may also increase blossom end rot.
Treatment : Remove the affected fruit so other fruits on the plant will develop normally. Keep the plants well watered. Mulch to maintain a more uniform moisture supply. Avoid cultivating, or hoeing, near the roots of tomato plants. Some gardeners like to add crushed eggshells to the transplant hole to fortify calcium intake.
