Peat pots tend to dry out fast, so you may have trouble keeping the medium damp enough.

Linda

Ok. Should I have used a seed starting mix for the peat pots? Should I transfer them to pots with seed starting mix?

I have noticed that some really sad looking tomato seedlings quickly rebound when taken to a final location outside. If that is an option, and were it me, I would transplant outside now. Everyone cannot do that of course.

Fish fertilizer diluted per directions should help a lot. Your soil looks dry to me in some of those peat pots. I use large Solo cups when I start peppers very early but this year all my plants were started later and are smaller so I transplanted to the small Solo cups. I give my husband a stack of them to drill holes in the bottom for drainage. Last year's cups were easy to clean and sterilize. It also looks to me like the plants in the Solo cups are growing faster, maybe more room for roots?

I think the medium is fine for the seedlings now. Their roots ought to be big enough to handle it. Fish emulsion will be fine and, as (poor) Albert (in zone 2b) says, if you can safely put them outside to harden off (in a shady spot to begin with), they will appreciate the extra light.

I did an experiment with plastic and peat pots a couple of years ago and learned that the seedlings grown in the plastic pots did better than the ones grown in the peat pots. I think it's all to do with water retention.

Linda

Could you give us the exact name of the "potting soil" you used please? Seed starting mix is fine for germinating seeds but not for growing plants and yours are plants now. Hopefully it isn't really soil but a soil-less mix that you used in which case it is fine. They need feeding and possibly less watering.

And before next year do some reading here of all the discussions about the problems - some of which you are discovering - with peat pots and why they should be avoided. Be sure you strip off those pots completely before planting.

Dave

ditto on the peat pots. Also, potting soil would trump seed starting mix in my book, and almost anything trumps the peat pots. I have had more trouble/complaints from people who use peat pots, although there always seem to be a few exceptions.

"Ok. Should I have used a seed starting mix for the peat pots? Should I transfer them to pots with seed starting mix?"

I re-use used plastic cell packs for seed starting. Have used peat pots in the past, a cute idea but they do have drawbacks. Assuming that you are in z-7, not sure?, and the ground is warm enough I'd plant them out now or soon. When planting try to very carefully remove some of the peat pot material while not disturbing the roots. Esp rip off the upper collar to prevent it acting as a moisture wick drying out the plant underground, and for tomatoes plant them a bit deeper than the pot level. Happy Harvest