Should I put a Magnolia in the ground

Semi shade in Ericaceous (acid) soil. They hate being moved and will sulk and probably not flower.

I have one in a pot. It didn't flower last year, so I repotted it into a slightly larger one and it is flowering well this year. However, it is still a fairly small one. I agree wtih Andrea that they prefer a bit of shade, particularly around the roots. But re the pH, my soil is neutral, and I have an old magolia that's doing ok on this soil. Have your tried feeding your magnolia?

Magnolias hate root disturbance. If you are thinking of repotting it or planting it out, spring offers the best chance of success. If it's a spring-flowering one, try to give it somewhere where it does not receive early morning light (a fast thaw after a frosty night will damage the flowers), also somewhere sheltered from strong winds