His instructions could have changed but I'm pretty sure that Brent mails these out with instructions to upgrade pot size during dormancy. When i got my 1gal (same size as OP), the roots were practically climbing out of the pot. You have more experience than I do, so I'm curious as to why you recommended a terracotta pot (do you mean a larger one?) if not just for increased water movement/evaporation/drainage. What is wrong with the ground, won't it grow out fastest there due to lack of soil constraints? Seriously asking, am a pine newb, and I want to learn as much as possible.