If you leave them in pots they won't become trees, but when the weather turns sour you can get them out of harms way, and that's a big plus when there's going to be high winds, heavy rain or hail in the forecast. If you put them in the ground, sometimes you don't find out until a month later when the sun moves its seasonal position you find out it's now shaded.
The reason I'd pick a northern (South facing) spot and not a Southern (North facing) one is because as we move further away from the Summer Solstice the sun drops lower into the Southern sky, so if it's planted South and North facing, spots that were sunny in June could be shaded by July.