Source: Rare Find Nursery (NJ)
Size shipped: #1 pot (measured about 3.5'!)
Planted: In ground, August 2020
First flowering: June 2021
Buy one at PlantingTree.com (affiliate link; supports this website)
(This plant stayed behind when I moved in 2021; therefore, the following text will receive no further updates.)
It's certainly nice to have a tree with such a nice height and branching structure straight out of the box (Rare Find has sent me nothing but winners, and as a bonus, they're in state!) ... but the tradeoff is that I could tell, even without removing the plant from its pot, that it was hopelessly rootbound. I didn't relish the prospect of doing a ton of manual root pruning on a magnolia, but I did do it... in mid-June.
Why such a long wait? Because I didn't want to plant out the sweetbay before first getting rid of the big Norway maple in the area of the planned planting. However, after we agreed with a local arborist to go ahead with the Norway maple job, it took them OVER A MONTH to actually come out and do it... and even then the stump grinder had to be a separate visit. So by the time the Norway maple was removed, it was mid-June and the weather was far too hot (and, somehow, lacking in rain!) to do the planting. So I finally gave up on waiting and just did the root pruning and put the tree back in the same pot, figuring that it would be too long and the roots would get too incorrigibly defective if I kept on delaying the root pruning until planting time.
And I appear to have been correct about that, as even after having been pruned, the roots had still regrown to the point of going down the sides of the pot by the time the stump grinder had done its thing and I could plant, which was at the beginning of August. I essentially planted the magnolia in the resulting pile of wood and bark chips, with the immediate surroundings mixed with compost and the ground underneath loosened as much as I could (which wasn't much, given the remaining very large maple roots), similar to how I had planted the Prague viburnum to avoid disturbing the arborvitae roots. The outlook for August 2020 unfortunately wasn't much cooler or rainier than June or July had been, so I deliberately picked a planting day right before three days that all had rain in the forecast (including Tropical Storm Isaias).
But despite such planting on the ground instead of in the ground, the sweetbay magnolia appeared to have rooted out quite nicely, as it was already anchored steadily enough for me to remove the stakes (originally set up in preparation for Tropical Storm Isaias, as I feared the effect such high winds could have on a new planting, especially since magnolias are known to be sensitive to torn roots from such shocks) in mid-September. I wouldn't be surprised if the manual root pruning had something to do with that, but I still wasn't expecting such quick anchorage given the unique nature of the site. The adequate lower branches (see photo) probably helped, as lower leaves and branches are most likely to feed the roots and thicken the trunk base; props to Rare Find for not removing them before shipping.