tomato blossom rot
I have three tomato plants in the same raised bed. Why would the middle one have rot on the bottom but the other two are fine. One is a yellow cherry and the other is a patio early girl. I did trim off some of the big leaves.
Certified GKH Gardening Expert
This is caused by a lack of calcium/magnesium. This can happen when a tomato needs more of it than it has available, and some need more than others.
This has a very simple cure. Dolomitic lime. This will provide calcium, and magnesium while keeping the pH stable.