Too cold overnight? Too hot in the tunnel during the day?
Isn't Zone 7b last frost date in April? If so, aren't you jumping the gun a little? Imo, they've been tortured by extreme temperatures. To save them keep them indoors until 1 week before official last frost date; pot them up into larger containers (bury the stem up to the first true leaves). Give them a hit of Epsom salts (1 tbsp per gal of water) one week after potting up.
I think you put your babies out too early.

This post was edited by uncle_t on Tue, Mar 5, 13 at 0:36

They look bad. I wouldn't count on them coming back.

My guess would be that you did over fert them. Just because you gave the same dose to other plants that are doing well does not mean that it's ok for tomato plants.

I'd start over and not fertilize until they're up and running.

I agree on the fertilizer. Generally I do not fertilize seedlings at all. Instead of giving up though I would flush really well with plain water.

Good luck.

Do yourself a favor.

Those plants are seriously stressed. So, even though it hurts, toss them and start over.

awwwww. Poor babies. ;-) Give 'em a good flush - what's to lose??

There may be a way out.

To me it looks like the mix is saturated with water and when that happens no nutrients can be taken up by the roots, nor oxygen.

You cerainly can start over if you wish, but you might consider trying to dry out that mix by placing the trays on a heat mat or something equivalent.

Then spray the foliage with dilute fish or seaweed prep , both of which are high in minor nutrients including P which is perhaps the one most needed now.

Don't add the fish or seaweed stuff to the mix directly b/c what you're trying to do is for the time being bypass any root uptake from the mix,

Just a suggstion, your choice.

And as others have said in a 7b zone I wouldn't be putting them out in a cold frame or hoop house at this time of year.

Carolyn

Thanks for the suggestions I think the cold was to much for them. I was going to plant them on plastic in the high tunnel in early April, that's why I have started them early. I thought if I left the heat off them during the warmer nights that would help harden them off. I'm not going to give up on them just yet because I have 130 plants. The 4 in the picture were just random ones I pulled out.

They seem to be doing okay today, they did not get worse. I put the Epsom Salt on them. I do not have fish/seaweed right now but I can get some. Do you think I will over do it if I put the fish on too?

Wait it out and see how they do,

I can't see that Epsom salts ( magnesium sulfate) can do anything, but I could see some P and other micronutrients from fish or seaweed helping.

The fertilizer you used probably never got into the seedlings since absorption thru the roots was blocked by the water saturated root system, so no, I don't ithink spraying just the foliage with very dilute fish or seaweed is going to cause problems.

So wait and see what happens first, and let us know,'

Carolyn

So, they are not getting worse and you used the Epsom Salt, so you watered them again, correct? Its really hard for me to see much in your picture which is pretty dark on my computer but it they were overly saturated and you watered them again, I would think they would be worse? I guess thats a question to Carolyn. If that is not happening then maybe the watering is flushing out the ferts, which, with the temps may well be the the source of the stress. Good luck with your babies - I hope they make it.

Yes, I just watered them yesterday with the Epsom Salt. The plants have not been overly saturated with water. In fact some of them were on the dry side and looked the same as the ones in the picture. I will let you know how they turn out. Thanks for all the suggestions!

Well I'm sure glad i did not give up on the plants. They are looking fantastic compared to how they looked early in the week. Below is a picture I took of them a little bit ago. I pinched off most of the dead leaves on the plants and I sprayed them down with fish fertilizer.

This post was edited by TomatoesAndThings on Sat, Mar 9, 13 at 11:24

Glad you waited it out and used the foliar dilute fish spray,

They look great from that first picture.

Did you also try to dry out those plants as well or at least not watering so much and at least trying to keep them warmer?

Carolyn

And they all lived happily ever after. Glad you got them thru it. Good job!