wilt

Hey guys, Does anyone know what's happening with my swett 100 Tomatoes pictured below? They're patio plants in grow bags in about 90-93* texas heat. There is space around the containers which I imagine would help with aeration and drying the soil out and I usually water them every other day...

I haven't been having much luck with cucumber seedlings. As soon as they get their third true leaf they start to yellow and die. I have tried two different brands and have tried jiffy pots, jiffy peat pots and direct to soil. Any ideas? I live in Bundy, subtropical climate. Thanks in advance.