Freeze Damage on Magnolias

Many of our customers Magnolia Trees have suffered severe damage or total kill on SOME of their Magnolias.  It was observed in early spring during our first lawn treatment round.  In most cases, we saw totally healthy Magnolia trees right next to severely damaged or dead trees.  Most of the dead trees are  in the 8-14 ft range.  We were asked if this could be herbicide damage.  We really did not know the answer??? We checked with other lawn care companies, landscapers, and Arborists.  They all had seen similar circumstances.  The one thing we did know is that some of the trees were in grass areas and some were in landscape beds, many feet away from treated grass areas.  This lead us to assume that it was not herbicide injury.  We found out that Dr. Alan Windam, plan pathologist from UT extension service, had seen the same issues.  It is his belief that these Magnolias suffered FREEZE DAMAGE.  They are unsure of the exact circumstances that caused some trees to suffer greatly and some to be uneffected, but assume it is possibly a small genetic difference in the various trees.