Tomato Troubles

I searched for something on this topic and couldn't find anything, so hopefully this isn't a repeat...

I have 9 tomato plants and most are doing great. I ran out of room in my SFG when I was planting (I overbought on plants because some of them looked like they weren't going to make it) so I had to plant two romas in my yard in the regular soil. They have been growing great until about a week ago when one of them started developing yellow leaves. There are no spots of any kind--just turning yellow and all the leaves feel damp. They are watered 1-2 times a week with a drip irrigation and the soil definitely feels wet. I'm thinking they are turning yellow from overwatering/poor drainage in the crappy soil. Does this seem correct to all you experts out there?

I closed the valve so it wouldn't get watered with the other plants this last time and I will probably just start watering it by hand for awhile (once a week). Should I clip off all the yellowing parts of the plant or is it best to just leave it alone?

Any advice I can get would be super helpful! This is only my second year with a garden so I'm still a struggling newbie. By the way, the bush is enormous and COVERED in tomatoes. They are all suddenly turning red in a hurry. Is it because the plant is stressed? Am I going to lose it altogether or is there hope for recovery?

Thanks in advance for any suggestions!

Welcome back to the forum. Have you amended the soil or recently fertilized those tomatoes with yellowing leaves? Are the leaves curling? Would you be able to post a photo?

I fertilized it a couple of weeks ago with Fertilome Blooming and Rooting (9-59- and it helped it flower like crazy. Up until a week ago it has been very healthy looking. I am actually surprised that this has suddenly happened. There is another Roma right next to it that is smaller and less healthy looking that is fine (they are both watered by a different dripper)

I dug down and stuck my finger in the soil and it is VERY wet...much wetter than I expected it to be.

I will try to get some pictures to post tomorrow when it's light out.

Hmmm... Check this site.
http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomLeaf/TomLeafKey.html