Ask a Consulting Arborist Q&A: Tree Health

Q: Why does our fruitless mulberry have soft spots, insects, and white fungus?

Thursday, December 31, 2015  

Q: We have a 55-year-old fruitless mulberry that is now having issues with soft spots, burrowing insects, and white fungus. Can you give us guidance on these issues? We love our huge tree and would be sick if we lost it. We live in Livermore, California, which is in the East Bay area.

A: Mulberry trees are usually fast growing and can have large sucker shoots that become branches, dense foliage, crossing branches, and long branches that have leveraging end weights. They commonly have decay in branches, trunks, and old pruning wounds. From the brief description, if is difficult to determine the extent of the deterioration of your tree, and I would recommend you contact a local Consulting Arborist to look at the tree.

If the tree has some soft wood and a generally sound trunk, it may be able to be pruned to retain some shade and reduce the size of the tree. Future pruning management will grow new branches in the remaining sound wood. If the trunk is badly decayed, or there are weak or split branch attachments, the tree may be able to be retained in a reduced foliar crown size.

The burrowing insects may be present in decaying wood. As long as the solid wood continues to outgrow the decaying wood, trees may be retained with management of the foliar crown reduced in balance with the trunk wood quality. if the decay is too severe, the risk of failure may be so great that if there are significant people or property targets, the options are either to move the targets or remove the tree.

Without a better description of the white fungus, it is hard to tell if it is a wood decay fungus or a mildew or superficial fungus. In the East Bay, there are several qualified Consulting Arborists that can assist you with a quality diagnosis.


Responder: Gordon Mann, RCA #480, Auburn, CA