MIght just be the exposure, but that soil sure looks dry. Kind of looks like the soil is pulling away from the walls, which is what happens when it dries out.

I've been watering them regularly but I thought they might be dying off from TOO much moisture?

What medium are they planted in and, are you SURE the soil is completely moist? This has been talked a lot about here, but it is difficult to thoroughly moisten dry potting/seedling soil. The top can look wet, but it can be bone dry underneath. The water just runs off down the sides. Once the roots get down to bone dry soil, the plant will suffer.

I just bought the Miracle Gro Seed Starting Potting Mix. Is the soil not being wet an issue even with days old seedlings though? I thought the roots wouldn't be long enough for that to matter but I'm only just starting these for the first time

Good mix to use. The roots are pretty much as long down below as the plant is long on top. If the soil an inch down is dry, the plants will keel over. I keep looking at the top picture, which seems to show a gap forming around the soil on the sides. That points to dried out soil that is shrinking. You might probe into one of the pots with a knife, and see if it looks wet underneath.

I've gone ahead and watered them well and will keep an eye out for any more seedling deaths :(

Peat pots really soak up moisture FAST so it's best to keep them well watered.

For next time, plastic pots are a lot better.

Linda

Thank you! I started them in peat pots because I'd read/heard that they're biodegradable and make moving the seedlings outdoors easier but you're probably right about the plastic pots for next time. I was thinking about using a recycle cardboard (i think) egg carton for some other seeds, do you have any experience with those?

Peat pots dry out really fast too.

I've used little peat pots and home-made newspaper pots. I'm around all day to make sure they have adequate water, but I discovered that the seedlings that I grew (at the same time) in individual yoghurt cups and little plastic pots actually grew better, and it's all to do with moisture retention.

Peat pots aren't even that great for transplanting - well they are easy, but when I pulled up my tomato plants at the end of the season, I was horrified to see that a lot of the roots were trapped inside the peat pots!

Newspaper pots are great for things like melons and squash that don't really like being transplanted, and the roots can grow through paper more easily than through peat pots.

I don't like the idea of egg cartons, but I've never actually tried them.

Linda

the first picture, the ones on the left look a bit dry, the two cubes on the right look about right. don't over water, just make sure that they stay damp, but not too wet. put plastic wrap around the bottom and sides of the seed tray.. they pull moisture out of the soil.