Tomato rotening

[headfullofbees]

Excessive magnesium actually blocks the absorption of calcium, there are many articles that state this. Epsom salts are not good unless there is a magnesium deficiency which is fairly uncommon. https://tomatogeek.com/epsom-salt-tomatoes/

So does excess potassium, which is more common, since we tend to add it.
Magnesium, as Chuck says, helps to balance things out.

 

[headfullofbees]

Better to make up a liquid feed of pelleted poultry manure, which is up to 6% calcium.
Calcium deficiency is, however, pretty rare.

 

[cntrlwagdnr]

We have been plagued with bottom end rot for a number of years, to the point that we almost quit growing them. But giving them an occasional feeding of garden lime/calcium solved it real quick. We do use the occasional dose of epsom salts too, but it never did anything for blossom end rot. It's the calcium that does it for us. Interestingly, the cherry and grape type tomatoes have never suffered from it.