I planted sweet 100 last year. They produced more into the summer than any other variety, but eventually stopped producing mid summer, and I yanked-em out. Maybe you're on to something there...

Uhhh, Sweet 100 is an indeterminate variety so yes, like all indeterminate varieties it will continue to grow and produce fruit - weather permitting - all season long unless killed by disease or a freeze.

Dave

Well, sure it's indeterminate. I always plant indeterminate varieties. but I figured that meant that if the vines could be kept green, they'd continue to produce. My experience is that indeterminate varieties produce for an extended period of time, but then they depart. That's evidently not the way it works. The vines that produce do die off. What is surprising me is that new vines are sprouting and RAPIDLY growing! Those new vines have loads of flowers.

Like dogwind above, in the past, when the vines finally start to brown out after several months of production, I just yank 'em. Wrong move, it seems. Clear out the dead vines, water like crazy, and stand back! I didn't do it but some high N fertilizer might be good to apply at this point.

We'll see if these new flowers actually fruit ...

High nitrogen will only produce nice green leaves, not fruit.

I pulled 15 plants today, but left 7 and trimmed them up a bit. Sun Gold is still producing, although I'm only picking a few tomatoes a day right now. We'll see how they all do the next couple months.

Yes, you're right, nitrogen fertilizer is a bad idea, especially now, with flowers out.

The issue will be fruit set, with nighttime lows around 75F and daytime highs around 100F. But Sweet 100s, I hear, are pretty tolerant of high temperatures. We'll see.