Cranberry, I've had difficulty growing San Marzano Redorta. Every year I have the same problem that you described. They are not disease resistant/tolerant, but then they don't claim to be.. This year I planted Celebrity tomatoes (by seed) twice. First planting was for the setting out in the garden. Second planting was for replacements to the San Marzano Redorta. So far I've replaced 3 of my 14 SM plants, and have another plant which looks a but suspect. Since your plants are still in the seedling stage, wouldn't planting seeds vs. purchasing plants be a better option? I not sure about when to plant in WI but it seems like you may have time to do this? You'd also have backups for potential future losses. I plant my seeds in a plastic flower planter and then move directly to the garden.

You'll find several discussion currently running about San Marzanos over on the Growing Tomatoes forum (liked near the top of this forum's front page). The discussions include plant sources.

As to the problems with yours, since they are still inside the best guess is over-fertilization. But that is just a guess without much more detail on their growing conditions. So if you can't find the answer in the threads already there, why not post on the tomato forum and include in your question details on you growing medium, watering and feeding schedule, size/age of the plants, and even a photo if you can.

Good luck.

Dave

Our growing season is pretty short. I feel like I'd be waaayy behind if I started again from seed. Shoot - I didn't even see the tomatoes forum. I'll check it out; thanks.