Done with non-hybrid tomatoes, especially grafted ones
I had a grafted tomato plant in a container on my patio this year. I also had a hybrid cherry tomato. The cherry tomato produced like gangbusters and is still going strong. I got ONE tomato off the grafted one. All the rest developed blossom end rot. Every. single. tomato. I finally got rid of it yesterday.
I thought the grafted plants were supposed to be resistant to things like that because they were grafted onto a hybrid root ball?
It's too late to help this year but I bought a bag of calcium carbonate powder (CalCarb) on Amazon this year. You mix with water and spray on underside of leaves.
Worked like a charm on my zucchini and squash plants to stop blossom end rot. Of course that meant there were plenty of fruits for the vine borers to destroy but that is a totally different issue.
Blossom end rot is an abiotic disorder, not really caused (or prevented by the root system), so grafted plants won't help.
The best way to prevent it is to keep the water consistent, and hope that soil temperatures are "normal" (not too cold or too hot). Can be tricky to do in containers, as they tend to dry out quickly.
It is a calcium deficiency in the fruit, but usually applying calcium doesn't help if the soil conditions are causing poor uptake. Calcium foliar sprays might help, but best to provide the right soil conditions.
>>"The best way to prevent it is to keep the water consistent, and hope that soil temperatures are "normal" (not too cold or too hot). Can be tricky to do in containers, as they tend to dry out quickly."<<
I'm curious as to how this relates to my situation. Circumstances cause me to plant tomatoes in 10 gallon clay pots right now, so I'm guessing the soil gets really hot in our recent 100 degree weather this summer (SoCal). I think I may get some blossom end rot at times, but every plant seems to rather quickly develop lower yellow leaves that dry up, and the condition then proceeds upward on the plant. I get tomatoes, but I'm thinking it's a watering issue. I check the soil and I water every other day, usually, unless it's been unusually hot or cool, and adjust accordingly. Usually yellow leaves indicate over-watering, but I'm wondering if super-heated soil might cause stress on the plant too.
I grow mostly OP or heirloom tomatoes from seed for the taste. I've noticed that while some early fruit have BER, it goes away as the season progresses. I've noticed occasional BER in hybrids as well. Most hybrid varieties are bred to resist wilt, nematodes, pests, etc. I don't think I've seen any advertised to resist BER.
I don't know where you are located but here in New England, this has been a horrible year for tomatoes, at least in my yard (my zucchini plants died, too). I have been buying plants from a local backyard grower so I can get one each of a dozen varieties. This was the first time I planted some of the plants under a plastic high tunnel (with sides rolled up and doors left open. Even with the sides rolled up, it easily gets over 100 F on sunny days. I did not have to water the plants even though they didn't get rained on. Plants outside are in pitiful shape from all the diseases this year but the ones in the high tunnel are their usual lush, strong plants. What a difference when they don't get rain spattered and affected by disease. It was so wet this year the ground in the high tunnel was moist enough.
Did you re-use soil from a previous year?
I don't think you can compare one variety to another.
I've been burying a handful of crushed eggshells under every tomato plant, use fish fertilizer to water when I transplant and then once a week for the first month or so (1/2 gallon of fish fertilizer mixed with water for each plant).
When I grew tomatoes in containers, cherry varieties always did better but still not as good as they do in the ground with lots of sun. Perhaps your container was too small and if it rained too much, nutrients were washed out of the soil.
I hope you will try again but perhaps limit the variety you choose to one that is appropriate for container growing.
My friend in Georgia grew her first container garden this year, it was a wash out due to excessive rain. But she reminded me, her neighbor told her to use Miracle Gro once a week and she said it made a big, immediate difference. My husband used to do that years back, when he was in charge of the garden. I think I'll give that a try next.