Quote Originally Posted by gypski
After it grows the third or fourth node and is a about 3"-4" in height. By then your cup should have a full root ball started.
When you transplant it, ya want to make sure the soil is dry. This makes it easier to handle, plus your going to water it anyway after the transplant. (to help keep the stress level down.)
I usually prepare my new container by adding the soil to it around an empty cup (the same size the seedling's in)
When I'm ready to transplant, I remove the empty cup and use the hole to plant in.