Planted in March in a 5 gal. bucket (with drain holes) with Miracle Grow potting soil. Every tomato so far has been black on the bottom half and unfit for consumption. Few have matured to the orange state and most are less than 2″ in dia. They are watered daily and have had some shading from intense sun with screen material. Any idea what is causing the apparent rot? Thanks, Don K.
Answer: It sounds like your plants are suffering from Blossom End Rot. This is a condition and not a disease, usually caused by a calcium deficiency brought on by fluctuating soil moisture or an excess of nitrogen in the soil. Some of the branded potting soils have added fertilizer or are nitrogen rich which is good for nice lush plants but bad for fruit. It could also be that the plants are wetter than you think (if you are watering daily), or the opposite, that they are drier than you think. Both have the same symptoms. You might want to try a moisture meter to check the conditions farther down in the pot than what you can feel. Or try the combined meters that will also tell you the pH of the soil: tomatoes want a nice 6.5 pH. You will also want to make sure you fertilize with a plant food designed for vegetables such as Hi-Yeild Garden Fertilizer or Tomato-tone, both formulated low in nitrogen and high in phosphorous to help the plant produce healthy blooms and fruits.
If you can correct the soil moisture you will be able to harvest perfect tomatoes.