Last year the only tomatoes that produced through fall were the ones I put a shade cloth over. I planted a total of 24 tomato plants last year. By July they were beginning to look pretty bad. I couldn’t figure out what was wrong but thought to try shading some of them to experiment. The six plants I put shade cloth over returned to healthy vibrant fruit bearing plants and those that were not covered pretty much died. Those that were covered produced well until the first frost. This year I’m covering them all. It was 60% shade cloth. I'm near Aiken, SC to give a perspective on latitude.
Last year was hot and I had to provide shade for my tomatoes also.