Could be physiological disorder. Start hardening off then set into the garden.

Not sure about scale, but boy, those look like small pots! I suspect at least the plants are somewhat stressed. The bumps on the leaves sure do look like edema. If not overwatering then maybe underfertilization of potassium.

I repotted them, since this is their first day of hardening off. They look pretty sad.

Repotted them after photo was taken. or is the photo after you potted up? Pot in pic look small.

Agree with Dan that there is an awfully lot of leaf edema showing for plants that are "not overwatered".

Dave

I let the pots dry out between waterings; they were light when I picked them up.

The weather in NE PA will be rainy and humid all week. They look even worse tonight than in the photo. What should I do?

High humidity and poor air circulation exacerbates edema. Edema is when the plant sucks up water faster than the leaves can release it. If the humidity is high, and the air isn't moving, the leaves can't release much.

"I let the pots dry out between waterings; they were light when I picked them up."

That is only one factor. Frequency of watering is also an issue. If pots are too samll for the root structure of the plant, if the ratio of free soil (to retain water over time) and amount of roots is out of whack then the roots will immediately suck up all the water and the leaves will swell. Then the little free soil dries out but as Dan said the leaves can't release all that moisture fast enough.

Don't know the potsize but as other have mentioned they look small for the size of the plants. A fan to improve air circulation also helps.

Dave

I repotted into 4-inch pots. Hoping for the best and that I can plant out soon. The weather is not cooperating.

From research, it looks like magnesium and iron deficiency problems. Strange, because I was watering every other time with Miracle-Gro. These are the tomatoes I was going to plant in the shelter garden. Are they going to make it?

That bottom picture with dying purple leaves doesn't look anything like your other pictures. The upper pictures show no signs of any serious nutrient deficiency. Not really clear from this set of pictures what your general situation is. Do you have dying plants with purple leaves, or abundant green leaves with some edema?

Sigh. I'm going to take another photo. Can you hang on? I'm panicking a bit because these are supposed to go into the shelter garden and without them, I have to buy. Be right back.

Note size of new pots.

OK, what I see here are pretty healthy plants with some edema. That edema will go away when the water situation stabilizes. Pots are still kinda small for plants this size. Frankly, when the plant is a lot bigger than the pot, something has to give. Betcha they were highly rootbound when you transplanted them from smaller pots.

They were! I've been gardening for seven years, and every year I learn something new. Thank you so much for diagnosing.

I still have to harden them off. Will they be okay in these pots for another week?

Also the purple, I have this until I take them out to be hardened off. The sun and warm temperatures make it go away just fine with no problems.

Get them outside ASAP as long as frost is over. It amazes me how this step can solve many pot related problems. Add a fan from day one next year to your seedling regimen.

Yep, they need to be outside in the ground asap. Still have to harden them off, but you should be able to do that in a week.

But what about the rain? Check out this forecast: https://forecast.weather.gov/MapClick.php?textField1=40.34&textField2=-75.93#.Wv2Kl00m6po

I really think there is a deficiency of some sort (first I though it's magnesium (or some of it at least), but it could also be manganese, etc, etc). Possibly edema as well, but I'm not very familiar with that. I would stop the feeding and try to get them in ground, which will put everything in normal parameters again. My guess is the medium pH is not quite right, possibly phosphorous overdose which also locks some micronutrients, it's not so easy to say, but for seedlings less is more (in terms of feeding and overall panicking).

The curled leaves look a bit like photos I've seen of tomato plants damaged by the persistent herbicides of the aminopyralid type. These herbicides are used on grasses (eg pasture, hayfields and cereal grains), to prevent broad-leafed plants. The horrific thing is they persist through the digestive system of animals such as horses and cattle, and they also persist through composting. So now some straw, hay, and composted manure may be contaminated and will destroy most broad-leafed plants. Google it, it is shocking.

Rain? Hard to believe that would hurt seedlings planted out. Unless it's driving, foliage destroying rain, clouds and mist would make life easier for them. Cold temperatures and bright sunlight are the possible stressors here.

It is driving rain...it's been raining for a solid week. I thought the problem was too much moisture, and it is EXTREMELY wet and humid. When I had them outside for their first day of hardening off they looked so bad that I took them back inside. They actually are drier and happier now. All that said, you have more experience than me. I will move them back outside to harden off, and then plant ASAP.

Agree that it is difficult to pin down any specific problems given the confusing photos as some pics show only edema while others show nutrient issues. But one thing is clear that plants this size have needed to either be transplanted outside long before now or should have been in much bigger containers than even 4" pots long before now.

Once you back the plant into a 'rootbound' corner the damage done to it in terms of both water and nutrients takes a great deal of time to recover from. And the longer it is in the corner the lower the odds of its recovery.

There is basically a 1.5:1 efficiency ratio of plant height in inches to size of pot required (so 1" to 1.5" tall plant in a 1" cell, 2-3" tall in a 3" etc.) and these plants appear to be easily 6-8" plus tall or more so if they were in pots that were less that 4" or even 4" pots you can easily see the problems that would create for them.

Dave

OK. They do look a bit better than before. But if you don't think the high humidity will make them worse, I'll put them outside tonight. We won't have sunshine for 3-4 days at least, though.

Sounds like perfect setting out weather.