New at this - need transplanting instructions

When to transplant bonsai seedlings from biodegradable pots?

I have not received any comments or help to my question which is disappointing and wondering if I’ve entered the info, pictures correctly?

Perhaps it is the wording of the question?
The use of biodegradable pots will not likely affect the timing for transplant.
Transplanting is normally determined by when the seedling requires more space or the group of seedlings should be separated.
I tend to separate seedlings early on to prevent root entanglement. The formation of a good root base is an important first step in growing Bonsai.
The groups pf seedlings could be gently separated at this point and placed in individual containers.

Seedlings are pretty strong (the pine family), I would let the soil dry out a bit so that you can dig under them and let the soil drop away without hurting the roots too much. Then put each in it’s own 4" pot for a year, then I put them in a 1 gal pot. The more soil space for the fine roots the better it will fare.
I like to make a pyramid, then fan the roots out with a chopstick to help with the nebari, pushing the new soil to hold each root in place so they are not just growing straight down. I do a lot of cuttings this way.

Thank you for much for responding, I’ll certainly follow your suggestions. I’d like to see these continue to grow, seeds were a gift from our son!

Thank you so much for responding … I’m a little anxious about the survival of these seedlings as I’m new at this! LOL

Thank you so much for responding … I’m a little anxious about the survival of these seedlings as I’m new at this! LOL

You can just use peat moss and perlite for the first 3 years of a trees growth, it drains well and is sterile, I mix my own but you can buy seedling starter mix, it’s the same thing, I just like more perlite than they usually mix, the important thing is to drain well so it makes it hard to over water and the roots don’t sit in wet soil all day, they drown.

Thank you for letting me know what kind, type of repotting soil as that was to be my next research project. I’m looking forward to getting the trees settled in for the next 3 years of growth! LS