Should I up pot my tomatoes or wait?

[Aya]

I know you're supposed to up pot when they have the first set of true leaves, but I'm not sure if these are considered true leaves or if they're just big seed leaves..

[rainbowgardener]

Those are seed leaves. The tiny beginnings of true leaves are just visible in the leaf crotch of some of them.

Wait until it has fully opened true leaves before up potting. They will be sturdier by then to withstand the transplanting and they will have more stem. You want more stem, because every time you transplant tomatoes you should bury them deeper than they were previously. You can see the little hairs on the stem of the tomato. When you bury them, some of those will become roots and you have thereby increased the root system of your plant, which is a good thing.

[hendi_alex]

I generally wait until true leaves form, but when breaking up a community pot, several plants are often at the more immature stage. I never notice any particular difference in growth, so am not sure that the formation of true leaves really matters. I notice some of your plants are very close together. IMO, the larger that you let them get, the more entwined the roots will be. So probably earlier repotting of those might work better.

[PaulF]

I say wait a while. I like for the true leaves to be very defined. If the roots are tangled, no big deal except be gentle when you tear them apart. In order to send the message to the plants to grow more roots, which is a main reason to transplant, root endings and hairs need to be damaged.....some but not a lot. That's the way I do it and have been pretty successful. There are always other opinions and methods that work.

[Aya]

Thanks everyone, these are the strongest seedlings I've been able to manage this year, so I wasn't sure when to give them more space..now I know!