I have grown these little seedlings from seeds in late February and wanted to know if I should thin them? I put three seeds in each pod, and they all seem to be thriving. Do you recommend thinning them down to one plant per pod? Also, when is the appropriate time to graduate them to a larger jiffy pot? Thanks so much for your help.
Yes, these should be thinned to one per cell.
You can either just snip the extras off at the soil line, or gently break them apart and replants the extras. We are still a good distance from when these can go out- roughly after Mother's Day so they will need repotting soon into a 4" pot.
Here is our vegetable profile page for tomato: