anytime. ive transplanted within a day or 2 of sprouting. just remember the younger it is, the more delicate, and the more careful you need to be
^Ditto. So while you can transplant a very young sprout, I would back up to how that came to be the situation in the first place. You should transplant when the plant has outgrown the pot it is in. So, if you are transplanting right away that is poor planning. Another reason to transplant might be that you put the plant in the wrong soil (such as soil with time-released ferts, which you definitely don't want) so you want to transplant before the plant gets killed by nute overdose, which again represents poor planning.
exactly. a while back i used a soil mix and decided agaist it after a few days. transplanted them with no problems. but like toasty said, its not recommended to transplants that early. if you need to it IS possible though
I start mine off in 5 litre ex mineral water containers. When they show sex the guys go on the compost heap, the girls get transplanted into 50 litre plus pots. I only transplant the once.