Do not do it now. I would wait until next spring especially if you have dry winters for this particular tree.

Is the tree you are considering pot-grown or B&B or what? A 10' tall Southern Magnolia should have a pretty big rootball. How large is the rootball on the one you are considering? Do you have the ability to handle a rootball that large?

As j0nd03 said, now is not the best time to plant a tree, but the odds of it surviving depends on many things including its current condition and how it's treated during and after planting. Planting it now is not the killer, but what it's gone through so far and what you have to do to it (especially root system preparation) when planting it can be. If your tree is pot-grown, be aware that it may require extensive root pruning to straighten out the pot-bound root system (a death sentence this time of year).

If it were me, I'd wait until fall to plant it. That should be the optimal time in your area, and it will make the work much easier (because it will be cooler). I'd also probably consider starting with a little smaller tree, which could establish more quickly and grow faster, if I was going to be doing the planting by myself. The link below may have some additional useful info for you.

Here is a link that might be useful: Planting a Tree or Shrub

This spring I planted a 10 ft-ish southern mag with a 4 foot spread out of a 7 gallon container. While examining the root system before planting I had to remove about 5 inches of a large root that was twisted around on the side of the rootball. I then lost the top 2 feet of the tree including the central leader along with the top two large branches below and then another foot of trunk below that. The tree appeared to be healthy when I planted it (sometime in late March/early April). The rootball never dried out. It has now flushed and has buds all over so I think it will be ok. My only point is, in my experience, this is a very fickle tree when it comes to planting. Do some research on all the people that have leaf drop after planting with this tree. You want to have everything in your favor when planting magnolia grandiflora.

Brandon brings up some good points about the condition it is currently in and maintenance. Do you know enough to watch them plant it and make any needed corrections to the rootball at that time?

To me, planting now would create much unnecessary stress.

in my neck of the woods ... most 'good' nurseries will tag a plant NOW, for fall sale and planting ... and that is what i would recommend in july/aug and sept if its still real hot ...

i wouldnt even do it in MI.. let alone any further south ... this time of year ...

total interference of the root system.. will make it very hard to the tree to hold its leaves during the high heat of summer ...

your nurseryman must have a lot of spares.. to not be concerned about planting more than one for you ...

also.. i would hesitate on planting a 10 foot tree .... large transplants have a much harder time recovering from the process ... i would recommend no more than 5 foot ... but a lot of that is my budget constraints ... [lol.. actually i would plant a one footer]

ken

The Teddy Bear variety is "designed" to reach a mature height of 15 to 20 feet with a spread of about 10 feet. It's more of a garden tree rather than a standard magnolia. You will want a plain ordinary magnolia grandiflora if you are wanting the large Southern Magnolia.

Any container trees can be planted during the summer as long as proper watering is done. Ground is a lot cooler than above ground container anyway.

Here is a link that might be useful: How to establish container trees round year

"Any container trees can be planted during the summer as long as proper watering is done."

The problem with that idea is that, in actuality, most container plants are at least somewhat pot-bound. When pot-bound stock is planted, root system issues need to be addressed. If significant root system manipulation is required, chances of survival with summer planting is greatly reduced. I'd change the above statement to something like, "Non-potbound container-grown trees can generally be successfully planted during the summer as long as they are properly planted and cared for, including keeping a close check on soil moisture."

Also, trees in a crowded location in the nursery can have too much "green" on the leaves and when placed in a full sun location, proceed to turn crispy. Had this happen to me earlier this summer after proper planting, mulching, and watering, the 100* consecutive day marathon was too much for the tree that was basically shaded most of the day in the nursery. Put it back in its pot and then in the shade for planting this fall and it is doing fine now.

Lou, just read your linked article. That doesn't apply to the great majority of nurseries who use black hollow pots instead of a rootmaker pot. He is even recommending fertilizer at planting. He also recomends frequent, light watering to establish...

No doubt it is unfortunate what passes for sale in a container at most nurseries as far as roots are concerned due in large part to the pots they are placed in with little/no afterthought about the root system, but that is our reality for the time being.