How to Control Blossom-End Rot on Tomatoes a disease, but rather a physiological disorder caused by a calcium imbalance within the plant.
Unfortunately, they probably have blossom-end rot. It is a common problem on tomatoes, peppers, eggplants, and squash caused by a low concentration of.
Technically, brown spots on tomatoes from blossom end rot is caused by this lack of calcium. For this reason, you often see it recommended.
Tomatoes need consistent water. In fact, skimping on watering earlier in the month is likely what caused blossom end rot in the first place.
A serious disorder of tomato, pepper, cucumber and eggplant, blossom end rot is an environmental problem (not fungal) most often caused by uneven watering.