I would plant something not likely to be affected by blight - a cole crop like cabbage, broccoli, etc, or okra, or a leafy green like lettuce, chard, mustard, turnips, etc.
So sorry. We've been there....... I know it's frustrating.
Do you have any white spots or similar infections on near by squash or cukes? I started getting the same rotten tomatoes yesterday after about an hour of looking and checking my other plants... I noticed I had been treating some downy mildew on my cantalope and on my summer squash. And that appears to be the cuplrip... long as you get it under control they should survive. But remove all infected leaves.
ARGGGGHHHHHH! I just killed all my tomato plants! crap. gardening is hard. gardening was way easier in Montana and in Cali. I feel like I never had any diseases.
So yes I have downy mildew on the the cuke plant next to my peppers. so I guess now I bag up that plant and dispose of it. cause it is actually getting way to big and taking over my entire garden and I can still start some more i time for fall or I can just take a break and plant some collards there around august.
I am more than bummed about the unnecessary death of my tomatoes but hey gardening is hard.
The tomato plants were definitely diseased. I thought it looked more like septoria leaf spot, which is also difficult to cure and spreads too easily. Your best bet was still to dispose of them regardless.
If you have powdery mildew, an organic copper fungicide will stop it. However, you'll need to keep using it if you leave the originally infected plant. (It may be easier to remove that plant as well.)
ETA: Collards are usually not affected by the same diseases as viney plants such as cucumbers, tomatoes, etc.