Q.Dying Desert Willow In NM
I have a very tall Desert Willow that is sick. It’s over 20 years old so I wonder if it is just dying slow from old age, or could it be Bark Beetles or some other strange malady? The bark loosens and falls off and the limb dies. Is there anything I can do to save this tree? It would be a sad loss for all the hummers and butterflies that come every year for the prolific and long lasting blooms. And of course, I would dearly miss the shade! Thank you. G.

Certified GKH Gardening Expert
According to a university fact sheet, desert willow lives 40 to 150 years, which is quite a spread. It is susceptible to root rot; has there been an abundance of rain lately, or has the soil around the tree become compacted, decreasing the drainage?
All the references say no known insect problems, but the tree does not tolerate overwatering.
Prune out the branches that are dying. An overall pruning may help. I suggest contacting your local extension agent, who may know of a pest or disease attributable to the trees in your area.
https://www.gardeningknowhow.com/ornamental/trees/desert-willow/pruning-desert-willows.htm
http://hort.ufl.edu/trees/CHILINA.pdf
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm