The magnolia bush is the smallest of the magnolia cultivars, reaching only about 15 feet in height, compared to magnolia trees, which can easily reach 30 to 40 feet in height. It is also called the star magnolia and is originally from Japan. You can prune it to be like a short tree by selectively removing the lower growth.
Prune away the lower growth from the bottom three or four feet of the bush. This will open up the base of the plant and make it look more like a tree. Make your cuts at a 45-degree angle to keep water from pooling at the cut. A cut should be made about an inch from the main branch or trunk so that the cut does not injure the bark of the bush.
Cut out branches that cross over each other or look diseased. The star magnolia does not like to have its growing tips cut off, so be careful to cut off a whole branch and not just the end of it. Typically, the branch will slowly die once a growing end is trimmed, and if the branch is large the flowering will be interrupted for a couple of years.
Leave the tree alone if you want a full rounded bush covered in blossoms. The flowers form at the tips of the branches so any pruning will reduce the flowers for a while. You should have blossoms from the ground to the top of the bush, producing a spectacular bush in the spring.