Question
I have a 30 year old Non Bearing Mulberry that has several branches that are completely dead. I'd say 90% of the trees branches are fine with healthy looking leaves. It has a 76 inch circumference trunk and stands about 40 feet high. I did notice where one branch was cut off, years back, there are holes. Thanks for any advice you may have.

Answer
Hi Edward:
From your description, your tree may have some level of internal decay. This decay can be caused by a variety of microorganisms (both fungal and bacterial).  These organisms often times enter the tree through a wound in the bark. Wounds can be caused by a lot of things including pruning cuts, insects and string trimmer damage.  The decay process is most often a slow, yet progressive process.  The only way to deal with this phenomena in trees is prevention. Preventing wounds can go a long way to help. Good nutrition is important also.  From your description, the tree still has a long life left.  Eventually, however the decay will weaken the tree to the point where many branches fail to leaf out and the tree may fail, especially during high winds or winter accumulation of snow or ice.

Best to monitor how well the tree leafs out each spring.  When it gets very thin, you may wish to remove it, especially if it may pose a hazard problem to person or property.  In the meantime, may sure it gets ample water and fertilizer.  This will help extend its life.

Regards
Steve