About a month or month and a half from that first transplanting, the seedlings should have grown to fill the surface of the tray. It’s time to move them up again. At this stage they are running out of food, and are becoming too crowded. They’ll either just sit there and not grow any more, or they’ll get leggy and be hard to make into nice plants or to transplant.
They are ready to transplant into small 1 to 1½ inch size pots at this time. You don’t have to be quite as concerned at this stage about perfectly sterile conditions as in the earlier stages. Make sure to label each pot as you go so you won’t miss any, or if only one type of seedlings are going in one sweater box, you can just put in one label for the box and label them before you take them out.
After they have grown to fill these pots, you can treat them like regular plants. If it is warm enough, you can move them outside in full shade for another couple of weeks and then start moving them into your regular growing areas.
