We recently lost our beautiful magnolia tree (over 25 years old) to scale. We took down the tree and dug out the stump and roots about 1 feet around the stump so we now have about a 3 foot diameter hole. Can we plant another magnolia in that hole?
If you are sure your tree died from Magnolia Scale you should be OK to replant another Magnolia. Magnolia Scale winters over on the tree not in the soil.
There are many new varieties of magnolia trees available to the Minnesota gardener. Pick one that is suited to your soil and light situation. I wanted a magnolia in my front yard, but it is clay and wet, so I picked the "Butterfly Magnolia" because it likes wet feet and it is thriving. Any of the major garden centers (Bachman's, Gerten's, etc) will have a nice selection.
Magnolias like a slightly acidic soil so I would get some good soil to fill around the root ball unless you have soil from the hole. Don't plant it in black dirt. Again check the requirements of the tree you select. The nursery center should be able to provide some guidance.
Here is a reference on planting trees and shrubs:
BTW, Magnolia scale is treatable: https://hort.extension.wisc.edu/articles/magnolia-scale/
With the new tree be vigilent in checking for any diseases just in case it wasn't scale that killed the tree,
Thanks you. The link to planting did not work. Is there a time of year that is best to plant a new tree?
You can plant your new tree any time. Just make sure to prepare the planting hole properly and be very diligent about water it. Moisture evaporates quickly in hot weather and the roots are not settled in. It will have time to root before it goes dormant. Try this line again it does work: https://extension.umn.edu/how/planting-and-transplanting-trees-and-shrubs