Last year when we planted our tomatoes we had high hopes of having sufficient fruit to make a ton of spaghetti sauce to get us through the year. What we didn’t know is that the soil we had was not good enough. Our plants grew tall, almost 6 feet. They were full and bushy with tons of small fruit and flowers. But before the fruit could grow full size and ripen…the bottom end, the blossom end furthest from the stem developed a black, sunken, leathery patch!
Upon research I learned that the condition is known as Blossom End Rot. This is most commonly caused by soil lacking in calcium and lack of consistent watering. It can also be triggered in the earliest set fruits if the soil is too cold or the plant is not sufficiently hardened off.
There are all kinds of chemical fertilizers to handle this issue, and if that is the route you want to take then please ask questions of the people at your local nursery or plant store. They should be able to direct you. But for me personally, I do not eat anything I cannot pronounce (meaning applied to the plant, absorbed by the plant, then consumed by me) or known to be chemical (man made).
What I have done is to dig the hole for the plant slightly deeper than is normal. At the bottom of the hole I added powdered milk, lime, and crushed eggshells. About ½ inch of dirt was then placed above that, and then the plant. Around the base of the plant I sprinkled crushed eggshells to slowly leach additional calcium into the soil with each additional rainfall. The crushed eggshells also have the added benefit of stopping slugs from approaching the stem of the tomato plant, as they do not like the feeling of slithering over the sharp edges of the shells. Through the season I can add powdered milk to the surface of the soil if it looks like even more calcium is needed.
To help combat the water end of the issue we have installed a sprinkler system (not perfected yet) and deeply mulched all the tomato plants to help protect the moisture from evaporating. As I write this we are in a heat spell with temps over 95 degrees Farenheit. The plants are looking great, the mulch and watering system seem to be working well. Our fruits are nearing full size and not one sign of the blossom end rot is here so far!
Check out my previous post on Tomatoes – Solanum lycopersicum