While you can dig up a magnolia tree and replant it in a container or in another part of the garden, there are some types of magnolia that transplant better than others. Generally, saucer magnolia are difficult to transplant because of their dense root system. Star magnolia is a hardy cultivar that transplants better. If you're unsure whether your magnolia tree will replant well, ask a horticulturist. Some trees may die if transplanted improperly.
When choosing where to replant your magnolia tree, find a site that is level and far from major walkways, roads or fence lines. Magnolia trees prefer to have their roots shaded. Wait until after your magnolia has bloomed for the season to dig it up and transplant it, since it will be more likely to survive than if you try to move it during the bloom time.
Once you've chosen a spot, dig a very large hole. The more soil you can move with the magnolia tree's root ball, the better your tree will fare once transplanted. Dig a hole that's two to three times as wide and deep as the root ball. You can always dig more if you realise your hole was not the right size, but don't dig up your magnolia and leave the tree out of the ground while you choose and prepare a site.
Moving the Tree
Once your new site is ready, you can dig up the magnolia. If the tree is too large to move alone, use a wheelbarrow to move it or ask someone to help you.
Use a flat spade and dig around the tree until you have made a complete circle, then work a garden shovel into the holes and gently tug upwards. Grasp the magnolia's trunk and gently pull up. Continue to work with the shovel if the tree still seems stuck. Try to get the root ball to come up with the tree. Once you have most of the root ball free, use garden scissors to cut the remaining roots.
Carry your magnolia over to the new site. If you need to make the hole larger, do so now. Place the magnolia in the hole, ensuring that it is resting at the same level as it was planted in the first site. You should be able to see a line in the soil. Spread the loose roots out with your fingers. Make sure the tree is vertically straight. Add soil on top of the roots; continue until you have mounded the soil over the hole, then water the tree to compact the soil.
Disturbing the root ball could reduce new branches, according to Van Plant, a magnolia nursery. Magnolia trees are beautiful but very messy, so avoid replanting them somewhere where their fallen flowers will be an eyesore.