Leaf miner damage. To control leafminers, spray the spinach with Spinosad to kill the existing larvae and then erect a lightweight floating row cover to keep the leafminer adults away. However, it is likely too late to be of any use this spring, because the days are long enough to trigger bolting. Plant spinach again in early fall for a fall and winter harvest. Spring spinach should always be harvested early before the leafminer infestations begin, or grown under row covers from seeding to harvest. Keep in mind that Spinosad does not kill leafminer adults, so row covers are the only permanent solution.

It sounds like you've been loving your plants to death. Daily bottom watering is more than enough to make them keel over dead. All the other stuff (tea, h. peroxide) makes it more difficult to pinpoint the culprit because any one of those things could've been disagreeable to your seedlings. Pepper seeds are basically complete, self-contained packages that can get all the way to full first leaves with nothing but light and a bit of water. Anything else introduced into the equation can cause an imbalance of one sort or another or just overwhelm the plant. Also, isn't Soilsponge a water retention medium? Retaining water while watering daily - I think you've got your answer right there. They probably just drowned. (With the caveat that what you describe is not what a drowned seedling looks like - the dark spot is not the usual symptom; but it's hard to tell given all the other variables you had going on there). On a side note, I believe your proportion of perlite is way, way too high. A quarter or maaaaaaybe a third perlite is OK, but 60 % perlite is going to leave huge gaps which are too big for the root structure to take hold. It'd be like trying to grow plants in a gravel bed, just to take a more extreme example - the roots need space but also need something to grab onto. Also your potting soil may already have perlite or vermiculite so your percentage perlite may actually be higher than 60 % - it could be that your seedlings roots just couldn't take hold in that mix. I would take some new seeds, put them in straight potting soil, do not add soilsponge, moisten the potting soil a bit once the seedling sprouts, give them the textbook 16 hours of light per day, and then give it a few drips of water every 4-5 days but only when it's obviously bone-dry and never when it seems to be already moist. See what happens. I think you'll get better results.

The first thing that comes to mind is the capillary mat. They tend to way OVER-water most things, keep the soil too wet. And overly wet soil kills more seedlings than just about everything else combined. Roots rot and the seedling slowly dies by drowning. Most of us tend to over-water our seedlings even without capillary matting so try getting them off it and see if some won't recover if it isn't already too late. Keep in mind that seedlings need the O2 they get from drier spaces in the soil just as much, if not more, than they need water. Many times less water is the cure. dave

Don't worry about the leaves, Pachypodium tend to drop them in the winter. I don't have a Gracilis, but my Lamerii has lost half its leaves and my Meridionale is completely bare. I gauge their health by how their bodies look rather than the leaves this time of year. I don't have an answer on the watering for you. I generally keep mine in one of those plastic propogation trays for a full year to keep the humidity up a bit as our dry winters always seemed to do in my seedlings before spring.