I planted two tomato plants this year, a Big Boy and a Better Boy, in containers on my balcony. My apartment balcony has a southern exposure, so they get plenty of sun. They were growing beautifully, had lots of blooms and started producing lots of tomatoes. Suddenly, I noticed a lot of brown leaves and the plants don't look so good anymore. The tomatoes are still there, but some of them are now on stems that are dying. We have had a lot of very hot, humid weather lately. I might have underestimated how large the plants would get because I now see roots at the base of the plants and they are very top heavy with no support. Any suggestions?