Definitely repot now; many young nursery and gift plants arrive already potbound, and this one really needs room for its roots. However, too big and the soil will stay wet too long, I'd vote for 6-8" size.

Use a peat-based potting mix rather than just garden soil. Some advocate a layer of gravel or chicken grit at the bottom to improve drainage, but others say it doesn't do that much.

Wait a few weeks before you fertilize so as to avoid burning tender new roots.

Other michelia growers? What am I missing?

Hope this helps!

Jim

Jim,
Thank you so much, I'll repot it this weekend and wait on fertilize as recommended. Warm regards.

I wouldnt repot so soon yet. Find a perfect spot for it and let it acclimatize there. Let it settle in its environment first. Being a little pot bound for a week longer isnt going to kill it, but a wrong location might (maybe sun is too intense and will burn the leaves, or not enough light, too drafty, etc). I read about some people putting their michelias in full sun, but in my dry and somewhat windy region, the leaves will turn brown after a few days in full sunlight. It depends on your region. So I grow mines in a bright, but shady area under another tree. It gets direct light when the sun is setting, but less intense than mid day sun.

After you figure that out, you can repot into a pot that is about 3 inches wider, not too much larger or there is a greater risk of root rot. As for potting mix, that might be a personal thing. Generally, try to use one that is fast draining and that will not compact over time too much, so it should contain things like wood chips and perlite. I used a generic brand and have had super awesome results. You can put gravel at the bottom of the pot, or in the saucer, better to put in the pot bottom. Don't let the soil sit in water that has drained into the saucer. Let soil dry a tiny bit before watering again.

Fertilize with a water soluble fertilizer for acid-loving plants (Azaleas and Camellias) every other week, but do not start so soon yet.

This is what I have done with my M. x alba that I have had for about 8 months. And my michelia actually look a whole lot better than the ones still at the nursery where they came from. I was very surprised when I went back there a few weeks ago.

Musaboru, Thank you so much for great info. I just got back from purchasing pot and soil, MG organic soil package said it's good for tropicals. I think I could add a little perlite? After hearing how pricy the plant is, it will be sinful to kill it with wrong soil/food/water/ and other growing condition. I guess, I should wait a week or so before I repot "My Michelia", oh yes, I have to make sure the pot size also. Thanks a mil.

I've learned that Michelias RESENT root disturbance, so don't beat the roots up.

This is particularly true on larger plants that are reloacted or transplanted even with massive rootballs being preserved during the move.

which michelia (magnolia) do you have? m. figo (if that is what you are growing) is perfectly hardy outdoors in my zone (8). point being that , if it is the hardier michelia, it does not necessarily have to live in a container in your zone if you have a spot in the garden for it. my m. figo is in full sun and is quite large (about 12'+ tall and wide). they want to grow into large shrubs/small trees.
just a thought that could make it easier and good luck with your plant.
btw, those are cheap plants in the nurseries of my area.
i paid $15 for a 3-footer in a 5 gal. container.

also, some helpful information below by a man who prefers container culture.

Here is a link that might be useful: michelia culture in containers