Hello michael19, I'll try and help you but need to know more before speculating what the problem may be, and if I can't help someone else may. You say all but the ones listed are healthy and irregular watering isn't an issue.

So tell me a little of what your doing and using. What potting soil did you use and a list of anything you've added to the soil since planting the seeds and how much. You stated Epson salt, so how much and was it also added to the healthy plants. Also do you live in a cooler region and are your plants on a window sill? Lastly were these plants transplanted into the present containers or did they grow from seed in the present containers.

To me they look over watered but you've stated otherwise. Pick up each container and gauge the weight to decide if they're saturated in the bottom half or third. A dry container will be very light while one saturated below will be on the heavy side.

I don't want to start guessing until you get back with the information but have you fertilized at all?

Thanks for taking a look!

I originally planted them in this seed starting mix in this 72-cell flat. They were on a heating mat controlled by a thermostat, set to about 83F. Once they had their true leaves, I separated the seedlings (I planted multiple per cell) and transplanted them into this Vigoro potting mix in square pots that were 3.5” across and 5” deep, and took them off the heat mat.

Before this initial transplantation I saw that some had yellowish leaves. I thought that perhaps they didn’t like the heat mat now that they had germinated, and I hoped that transplanting them (and getting them off the heat mat) would help. However, the yellowing got worse. I fertilized the yellow seedlings with very dilute Miracle-Gro 15-30-15 (1/2 teaspoon per gallon of water) and put a fan on all of the seedlings. Around this time I posted this question. The consensus there was that the potting soil was holding too much moisture (I hadn’t noticed that it was advertised as retaining moisture), so I re-transplanted them into this Miracle Gro potting mix. When I re-transplanted them I also put them into smaller pots (about 3” across by 3” deep), so that they would dry out faster. Over the course of a couple of weeks the yellowing went away.

Backing up: before the re-transplanting, some of the seedlings had purple undersides and mild twisting of the leaves. (The Cherokee Purple seedlings definitely had this; I’m not sure which others had it.) It didn’t seem to be causing any problems, though, so I didn’t worry about it. When the curling got worse, I thought perhaps it was left over from being too damp, and hoped that it would get fixed by the re-transplanting like the yellowing got fixed, but the twisting/curling has gotten slowly worse. The Cherokee Purple seedlings did not get the initial fertilizer, since they weren’t yellowing. However, the Omar’s Lebanese and Brandywine probably did get the fertilizer, since they were yellow. So there doesn’t seem to be any correlation between these seedlings and the ones that were previously yellow (and previously received dilute fertilizer). The only pattern I can see right now is that it follows the variety: if one seedling of a variety is affected, all are.

A couple weeks after the initial fertilization, I fertilized all of the seedlings, again with the same dilute fertilizer. A week or so after that, I watered all of the seedlings with 1 tablespoon of Epsom salt per gallon of water, in case the magnesium would help with the purple leaves. This was only a couple of days ago, which is why the potting soil is still damp in the photos. The Epsom salt may have helped with the purple coloration, but it hasn’t helped the twisting so far.

The seedlings aren’t near a window. We’ve had the heat set at 66F, and it’s been pretty consistently that temperature inside except for a few days recently when it’s gotten closer to 80F. The twisting started before those hot days, though.

As mentioned, I had a fan blowing on all of the seedlings, but I stopped that about a week ago in case it was somehow causing the twisting. So far stopping the fan hasn’t made a difference. I think I’ll turn it back on to help the soil dry out faster again.

It looks like there are aphids inside the lower leaf on the Brandywine????

I think those raised bumps are edema, which means too much water........

Don't feel bad. I'm having trouble with water-retentive potting mix this year too :(.

In case it helps, I had trouble with some eggplant seedlings wilting after transplant. I put it down to using some very soggy potting mix which I had mixed with some ultra-cold water from the well. They reacted, either to the cold or too much moisture and eventually dropped their outer leaves.

Linda

This was such an informative post..thank you everyone! I had been wondering if it might have been the seed starting mix causing problems. I used Miracle Grow seed starting mix for the first time, which was great for germination, but they don’t seem to be doing so well now - too wet and seems to stay wet for quite a while, even with a fan on.

Man, glad I saw this thread. I too have had some odd with the tomato seedlings this year. Been doing the same thing I've been doing for years... but this year I'm having problems with the same kinds of symptoms like others have said.

My only difference this year? I'm not using my usual pro-mix I've been using for ages. The store was out out it last time I need to get some mix, so I picked up a couple bags of Master Gardener instead.

The first bag I used for mostly flower and brassica seedlings, they are mostly acting like they should. Need more attention than usual, and higher fail rates on early herbs. I cracked open the second bag for my tomatoes and some other stuff, and some are not acting like they should. Notably eggplants and tomatillo, though my peppers aren't up to their usual snuff either. My additional rounds of herbs have been much more fussy than usual too.

I've had that same purple-underside-and-curling leaf problem in my tomato seedlings that just began this week. I started them (Mountain Merit late blight-resistant) in Rockwool, because our plan is to try hydroponics in the fall, and wanted to see how it goes. I used a hydroponic nutrient solution after they had their first true leaves. Everything was fine, but I think I overwatered them just ONE day (let them soak in the diluted solution for about 12 hours, since the cubes seemed dry on top). A day or so later, the seedlings looked so sad and purple! From what I've read, my hypothesis is that they are suffering a nutrient deficiency because of overwatering (the overwatering causing the nutrient solution to run out the bottom of the rockwool). Does that make sense?

Anyway, I potted the poor things into Miracle Gro potting soil (the one that protects against over-and under-watering!), added almost no water to the mix so the rockwool could dry out, and topped them off with a couple ounces of diluted Miracle Gro liquid fertilizer. This morning the purple has resolved, and the curly leaves don't seem to be progressing (although the previously affected leaves don't look any better).

The lettuce and kale seem fine in the little rockwool cubes for now, but I'm hoping to get them outdoors or into the cold frame before they start something!