I wouldn’t believe it if I didn’t see it with my own eyes. The very same day I used this clever remedy I stopped seeing the dreaded blossom-end rot that has attacked my tomatoes and zucchini since I started gardening. Brace yourself for the tip of the decade: ground egg shells.
I kid you not, ground egg shells is the only thing I will ever use. I did a bit of research to find that abnormal cell growth (resulting in rotting) is caused by a lack of calcium the plant needs for strength and to fight off stress. If you compost, no doubt you throw in your egg shells too. So save one egg shell per each affected plant, let it dry out (you can use the oven on the lowest temperature) and grind the shells (just short of a powder). Dust the soil around each plant with the ground shells right after you water the plant so the shells stay in place for each watering after that. You will not only help the plants lick the problem, but the plants will begin to appear stronger and the fruit you harvest will be richer in flavor and color. Awesome!
(More info about tomatoes.)