I really am an idiot.
I spent money on really nice bagged potting mix to start my little plants in. I spent money on little plastic pots. I spent money on seeds. I spent time planting the seeds, potting each little plant into its own pot, and babying them along, hoping for some late tomatoes and pretty flowers next year.
And then I thought, "They might need just a bit of nitrogen if they're going to stay in these pots for a while." I put two teaspoons of Urea (46-0-0) in a gallon of water and set the pots in a tray to soak it up.
What was I thinking???? (The question is probably not even relevant because I'm not sure I was thinking at all.)
When I looked at the plants the next morning, I knew immediately that I had screwed up.
It was like giving a baby two or three dozen cups of coffee.
By day three after I burned their little roots off with that supercharged nitrogen water, it was apparent that most of them weren't going to make it. I took the three that looked the least ill and put them in the garden, trying to knock off as much of the contaminated potting mix as I could. But I doubt they'll survive since the sun is so intensely hot.
This morning two of the Foxglove plants are wilted over and it doesn't look like they'll recover (but that could be from their roots being baked by the sun through their little pots!). The leaves on the little purple coneflower seedlings are starting to turn brown on the edges too. I moved the healthiest of the coneflowers into new pots, again, trying to knock as much of the contaminated potting mix off of their roots as I could. The orange coneflowers had just come up, so I hope I got them pricked out in time and that they will be ok. The artichoke plant still seems ok too, but just as a precaution it got moved into a new pot as well.
All of the contaminated potting mix will go into the compost bin with the remains of one of my poblano pepper plants that I killed by overwatering (again, more isn't always better).
Sigh.