I have 12 Tomato plants, planted two to a pot in very large plastic pots with proper drainage holes. I used good quality peat based potting mix and have not fed them at all. The weather here has been off and on wet and hot and sunny. I would say at least 2 days a week of rain. I have never seen this before. I had my plants in pots last year as well and they didn't look like this. The stems are curling under and the leaves are limpish, but the plants are continuing to grow and produce flowers.