Q.Why are branches in my magnolia tree dying?
I have a magnolia tree that is 5 or 6 years old and stands about 15 ft high. I noticed that the leaves seem to be thinning out, then noticed that some of the branches are bare. The bare branches are dead, as they snap off easily. At first it was just one branch near the top but now several branches throughout the tree are also bare and seem to be dying. Why is this happening and can I save this tree?
I would still consider your tree a fairly new planting. Sufficient watering needs to be maintained for your tree. I would prune up any dead material on your tree and water on a regular basis. Wait and see is my best advice.
Here is an excellent article about growing requirements of a magnolia tree.
https://www.gardeningknowhow.com/ornamental/trees/magnolia/magnolia-tree-care.htm