I've had EBs for about 7-8 years, then 5 years, and now I'm gone. This year, I have more BER than I've ever seen on my plants before AND I diligently gave them the "snack" 1x week from when they were 2 feet tall and just as blossoms started. Now I know it's not a guarantee ... Yet I 'm optimistic ...
First, is anything too late? I have 9 good plants with plenty of green tomatoes. Others look good so far (e.g. a combination of BER and non-BER on the same plant). One or two rotted before blushing. I think it's Brandywine. It seems to me late this season, I just have to deal with it / cut off the poor ones. What if it's not too late? Is this once I add some kind of lime? Secondly, the cause? In VA, it was pretty hot and humid. I have began late this year, planting in late May instead of mid-May. I do use variations I haven't used before, including Early Girl, Big Boy, and Celebrity. (And Mortgage Lifter and Brandywine, but they're behind). I used Jersey Boy in the past. Maybe because of all three???