First thing, I failed to take photos for you all and I will not be able to for a few days.. Sorry

I had several tomato plants of different varieties that got what appeared to be early blight (yellow leaves, black spots, progressing from the ground up). I am only home on weekends and have a drip system to water while I am gone so unfortunately by the time I noticed it, the blight had progressed up the plants quite a bit.

I got some fungicide spray, cut off all the branches that were yellow and sprayed the hell out of all the plants until they were dripping.

The following week when I was back in town, the yellowing had spread upward a few branches so I again cut the yellow ones off, and sprayed it again (I also hit them the next day with baking soda solution). At this point there wasn't much of the plants left, just the very upper branches. I figured it wasn't going to work but I let them go another week.

This last weekend, there is still a hint of yellowing further up and I almost yanked them all out and gave up, but I noticed that the lower portions where I cut off all the branches are now growing new branches. Quite a few actually and they look healthy and green.

Is this common? Should I still give up and yank them all out? Or let them go at this point and see what happens?