Stanhig, not sure about the seedlings, but nice greenhouse you got for them anyway. Good luck on finding out solution to your problem.

they look a little on the dry side. also make sure the light is right down close to them, from what I've heard the lights should only be a few inches above the plants.
I do metal halide lighting and natural light in a greenhouse, so maybe someone else can chime in on that.

I do have the lights positioned 1" or so above the plants.

The soil seems to be moist around the roots.

There isn't a lot of soil for them to dig their roots into. At that size, I'd transplant the seedlings into 16-oz. plastic or styrofoam drinking cups, 1 in each. If you use styrofoam, you can write on them with a ball-point pen, pressing down, to label them. Fill the cups up to the top with planting soil so the exposed stems are now buried. Don't fertilize. Seedlings don't need it.

The yellowing drooping seedlings look as though they aren't getting enough light, but if you have them close to the light that must not be the problem.

What kind of planting soil did you use? Maybe it's related to that?

Sorry, Stan. You said what kind of growing mix you used. It should be fine.

Stan, I tend to agree with those that posted above, lack of light and not nearly enough depth to the growing material that they are planted in. Mine are in M.G. seed starting mix, but are in deeper seed cells and are and get the natural daylight all day. I open the lid up a little every day to ventilate it and they get the natural breezes. They are growing nicely, the oldest ones have just started getting their first set of their true leaves, but they are nice and green with no apparent problems.

Even a very small tomato plant can have surprising root growth. If you go to the thread in this link and scroll down a way, I posted a link to a picture that shows that, to some extent.

Just my .02 but, I think think if it were me, I would give them better light for a few days, water a little if needed and pot them up into individual cups with enough room for the roots to grow like they should. I would suggest the 16 Oz. cups also.
Good luck and keep us posted.
Bill P.

Looks like not enough potting soil. I would NOT try to correct the problem at this time. continue as you are and transplant into 8 to 12oz pots when they get two true leaves.
plant them deep (up to plantbed leaves). water them with one half stregth fish fertlizer-5-1-1. your plants will green up in 8 to 10 days.you have not hurt your plants they will be just FINE Good luck and have a great season Bill

I agree with Bill - too little light and overcrowding have made them quite leggy and insufficient soil won't allow them to wait for true leaf development. It's ok to germinate them thick like this but then immediate transplanting is almost always needed in my experience.

Transplant them now into individual cell packs or cups - whatever you plan to use - plant them deep to just below the leaves in a good potting mix, increase the light they get, and plan a VERY light, diluted feeding for them in about a week.

Good luck - they will bounce back. ;)

Dave

The reason I suggest no fertilizer, at least for now, is that Miracle Grow Seed Starting Mix already has fertilizer in it, though I don't know how much. It should be enough to tide the plants over at transplant, particularly if you add more of the mix. I'd start the very light diluted feeding when they develop the first leaf buds, and it could be very soon. They seem to suddenly pop out.

Many of you have confirmed my thoughts, the soil is too shallow and the plants are overcrowded. I am planning to transplant into 16 oz cups ASAP! Thanks for all the advice, this is a great forum!