Can you post a pic? That would help. Otherwise it sounds like they need fertilizing. Go easy on the Esalts unless you know for a fact your soil is low in Mag. It is possible to OVER-use it.

Dave

In particular, Epsom Salt (which is magnesium sulfate) makes magnesium replace calcium in plant uptake. You end up with calcium deficiency, even if there is plenty of calcium in the soil. Epsom salt is not magic growth powder. It's a supplement that should be aimed at a recognized deficiency. In fact, magnesium deficiencies in soils are fairly rare.

Lime green leaves could indicate a range of nutrient deficiencies. Calcium, magnesium, manganese, sulfur, etc. A soil test would be smart.

Now the fact that you see the same color in plants that have yet to be planted out suggests a problem more widespread than nutrients in your bed.

That's what I'm thinking. None of the others look like that. Even right next to it, a cherry tomato is deep green.

I'll get a photo

There are also holes. It's not wilty or anything. We have had a couple weeks of unseasonably cool weather, 60's-70's during the day, low 40's at night.

I'd just give a dose of a well balanced fertilizer, something that also includes micro-nutrients, and see if that didn't solve the problem.

Dave

What is 4-6-6 fertilizer ? Is it organic ?

At any event it has much too little Nitrogen at this stage.

A yellow color like that, tells me (first) that it is not getting N and/or getting too much water.

Sey

Don't do anything too drastic since your yellow leaves are probably a result of the weather more than anything. A few warm days in a row and you should see an improvement. You could fertilize but keep it reasonable and don't use any more Epsom salt. If the color really bothers you you could spray with chelated iron but this situation usually corrects itself.

My tomatoes are green except for two and they both are striped cavern, but we've have had too much rain for too long in PA, I know it's not needing fertilizer, this type I'm guessing is just not as good as the others dealing with this weather. If you have had this weather too it might just be weather related.

Well, the odd thing is, it's only the San Marzano's that look like this. One is in the garden, the other two are in a cold frame, all the same color. The Sungold cherries, Brandywine and chocolate krim are nice and green, both garden and cold frame.

Same here one is still in a pot and the other is in the ground both exhibiting the same yellowing color.

I know some peppers have different shade of green ( quite common), eg banana, gypsy, cubanelle have very light green color ( Just like their unripe peppers) and Polano has the dark green foliage.

Right now I have a Kumato (F3) that has the darkest green of the rest of 30 varieties and Silvery Fir Tree has the lightest shade of green.

I have grown some version of SanMarzano many years ago but I cannot remember it being different in foliage color.

Sey