I have successfully sprouted 5 Royal Poinciana's from seeds. They are now about 2-3 weeks old and about 8" tall. They are currently in 4" pots.

I have never done this before, did it on a lark, was surprised they actually sprouted, and now need some help!

When should I move them to a larger pot? What size pot should I move up to next? When should I do it again? How big should they be before I put them in the ground?

I understand they will need frost protection in the winter, at least for a few years.

Thanks in advance for any suggestions!