A. Blossom-End Rot
Twice this week someone asked me why their tomatoes look like the ones pictured below.
Blossom-end rot is not a disease. It is a disorder within the plant do to a calcium imbalance. (Avoiding blossom-end rot relies on the proper supply of water and calcium to the ripening fruit.) Blossom-end rot does not spread from plant to plant, or from fruit to fruit. (The same disorder can happen to peppers, squash, cucumbers, and melons.)
Water soaked lessons first appear on the blossom side when the fruit is about 1/2 to 1/3 in size. As the fruit develops, the spot darkens and grows. This fruits should be picked and discarded.
There are various causes to blossom-end rot. Improper hardening off of tomato seedlings, starting plants outdoors in cold soil, poor soil conditions, drought or excessive moisture, and not maintaining a soil pH of around 6.5.
Blossom end rot is not a death sentence for your tomatoes plants. If treated, the plants can go on to produce ripe,red (yellow, orange etc.) tomatoes. Before planting, add crushed eggshells to the bottom of the hole. Sprinkle lime around the plants as needed, fallowing directions on the bag. Once blossom-end rot strikes, a mixture of 1/2 cup Epsom Salts to one gallon of water can be applied weekly to each tomato plant.