Magnolia grandiflora die back
Hi - I planted this particular magnolia in 1994, when it was all of 24" high. It is sheltered from the worst of the drying west winds by our house. It has done well ever since - even in years when we have experienced severe low temps - such as this past December/January. Most of this tree now seems dead - at least 60%. Do you think is the result from this past winter - or something more like verticillium wilt? Thanks!
This looks like winter damage on the magnolia. Many broadleaf evergreens were subject to this due to our cold winter, fluctuating temperatures and dry periods.
All you can do is wait for new growth as the weather warms up this spring. If the leaf buds were not damaged, new leaves will develop and the old ones will drop off. If it does not produce new growth, the top will be bare.
You can send us additional photos if you notice more symptoms.
Here is more information on winter damage https://extension.umd.edu/hgic/winter-damage-trees-and-shrubs