Hi Krolik, How's your plant doing? Here are a couple of thoughts. 1, Travel can be stressful for plants, they can pick up exposure to who knows what. 2, Bathroom humidity, It may not dry out enough, in there, to kill unwanted organisms, or let the plant cells move water. Consider moving the plant out of there for a few days, or a couple of weeks. Just give it a light morning spritz in it's new home. A flor. plant light -10$ and timer -8$ if the light needs adjusting+ a little, somewhere else. 3, Light anti-fungals/microbials, Neem oil from Logee's, that stuff is good! Meanwhile, have you tried watering with a little green tea, or black tea or coffee that's been thinned, or a spray of water and white vinegar, say from 1/10th to 1/3rd vinegar? And there's lysol spray, or other similar cheap substitute [saw that in gardenweb, just don't remember if it was on begonias]. My begonias perk up with the vinegar spray. One liked half cup of old coffee in its quart+ watering pot too. 4, Soil changes/repot.I had an ailing Sophie Cecile, one I had growing on from cuttings. I took a chance with it, because I didn't want to throw it out. I repotted it, down a little, because of fewer roots, with a little good soil from the yard. The soil had a little clay, a tiny bit of wood ash, some peaty compost, and maybe a little dog residue. They are supposed to like a little clay, and potash is good for fighting ills, and the texture was open from the plant material. It turns out that there's something in dung preferably cow, that helps fight off some virus or fungus or other. It was happy at the end of the summer,when it came out from under a shrub. I'm hoping that you can hold out till spring when you can set it in a protected spot.

Could be a fungus like Vladimir said, could also be an insect egg or just dirt on a bit of fluff. However, I'm more concerned with how dusty the leaves are. I may just be dust or it could be the beginnings of a spider mite infestation. It's a good idea to wash off the leaves from time to time, like maybe every 4-6 weeks. Take them outside and hose them off, or if that's not possible, put them in the shower and shower them off with cool water. Then let them drain well and put them back where they were. It helps prevent spider mites as they're attracted to dusty plants. And your plants love the rinsing off!

As Mule said the black spots aren't all that uncommon and aren't the real problem. They are just engorged hair follicles for the most part from the stressed transpiration. IMO the fertilizing regimen is the issue - way too much - given the leaf edges in the pic that were already showing signs of burn. Not only do young seedlings not need all that, they won't tolerate all that. The so-called "organic potting mixes" alone have been known to cause N burn issues because they insist on including things like chicken manure. And then to that you added all the other stuff. Why all the heavy feeding? Established plants, fine. Young seedlings, no. They can easily be grown to transplant size with no supplementation at all. Not that it is ideal, but it is possible and done by many with no problems. So I'd suggest laying off all the fertilizer stuff with the next batch if you are going to be using that same mix. And if you are going to use vermicompost tea then it has to be WELL diluted to almost no color to avoid burning. Add to that the heat and you end up with highly stressed seedlings with fried, stiff, curled under edges that are working overtime to transpire. Don't get so caught up in all the "organic" label marketing hype ("organic seeds" and "organic seed starting mix", etc.) that you forget that organics can kill plants too when improperly used. Are these plants done for? No, not IMO. But I'd transplant them into fresh potting mix - preferably a standard one with no fertilizers - and give them some time to recover. You'll lose some leaves but the plants as a whole should recover. JMO Dave

That's a fair point. In Montreal, your growing season is pretty much May-September. We're at the end of May, and you're not even sure you have seedlings. So you've used up about a quarter of your growing season looking for seedlings. Unless you're wedded to these particular plants, buying larger plants at this time might be smart. No, tomatoes don't take a long time to grow as seedlings, as long as they're kept warm (70-75F), and they get plenty of light. But even then, it'll be several weeks before you're ready to plant out.