So far, so good with my tomatoes. Last year all the tomatoes had late blight which was disappointing.

Here's some reading for blossom end rot

Here is a link that might be useful: USask Gardenline

When I plant, and several times afterwards, I add dry milk powder to the soil. This adds calcium. It also helps to remove the lowest leaves. Marg

Crushed eggshells or bonemeal work as well.

I only grow cherry tomatoes now. They don't seem to get it, maybe because each fruit is so small?

Thanks fellow gardeners, and also thanks Pudge for the reminder to read USask Gardenline.

With any luck the rest of the tomatoes to come won't have it.