What's happening with my tomato plants??

I'm at a total loss. I don't know what to do with or what happened to my poor tomato babies... I did not start these from seed. They were purchased from a big box store. They were doing fine, I had them in a 25 gallon pot. I had two plants in there one of them became sick, so I took the other plant out to avoid it catching any type of fungus. I water on a regular schedule. I fertilize. The soil was not water logged. We purchased the topsoil from a wholesale company and used this soil throughout the rest of the garden. These are/were Celebrity tomatoes. I have another (inground) row with (4) tomato plantd and my Roma tomato plant now has this discoloration on its leaves -last pic-. 
Any help or advice, constructive criticism ANYTHING is greatly appreciated! 
Thanks! 
-A.

Hello mandiroses, and welcome to the SFG forum!

Square Foot Gardening doesn't use topsoil, or use the "f" word (you know, the one that starts "F-E-R-T"). It's based on the techniques developed by Mel Bartholomew and described in the nearly sacred book, All New Square Foot Gardening (3rd ed.).

That said, very said to hear about your tomato plants   . Did you intend to include pictures? Please describe what happened. Did the plants dry up, or wilt and become brown?

I think San Antonio has similar weather to over here in lower, lower CA. Which means lots of consistent humidity. And my tomatoes lower limbs frequently wilt and turn brown. The only thing that keeps the plant alive is that the top/tip can outgrow the condition.

So what I'm going to suggest may be completely off the wall. But my feeling is that what is happening is a form of the same mildew that attacks other plants, especially squash and peas. Back  in the 1940s, Canadian researchers discovered that a mix of milk and water sprayed on plants would suppress the mildew. So I've been spraying my tomatoes with a mix. I was able to nurse several of my tomato plants through the winter and one of them is still bearing fruit. So ... maybe I'm on to something. Anyway, it's inexpensive to try -- you can even use powdered milk.

Well, now that I've give a crazy answer, maybe some more experienced gardeners will have better suggestions.

Happy Gardening!

Hi Mandiroses, and welcome!  Pictures would be helpful here…or a detailed description including dates of transplanting and is there any new growth? 

I agree with markqz if it’s powdery mildew, a milk and water 1/2 and half works great. I use cheap dry milk for this….reconstituted of course!  

More info would be good, and I highly recommend the Mel Bartholomew book!

Mandirose, A milk and water solution is good for suppressing powdery mildew. If it gets out of control, Neem oil mixed per instruction is the next level. Caution: always spray at sundown so it has time to dry before the bees return the next morning.

I don't see any mention (by the original poster) that should lead us to believe that this is powdery mildew.  I get powdery mildew on my peas every year but have never had powdery mildew on my tomatoes.  I don't get why our answers have been directed to powdery mildew.  There is no evidence of this.

Can you get us a pic or two, mandi?