Question: My mother’s mimosa tree was fine May 24. Something has attacked it. I attached before-and-after photos, with close-ups of a couple of damaged areas. Please advise what we should do.
It looks like carpenter bee nesting damage. They usually bore holes into dead wood, so I am guessing that the limb may have been under stress and has been dead for a while.
Carpenter bees are large and resemble bumble bees but fly faster and more zig-zaggy. They are as brightly colored as bumblebees.
With that much apparent damage, there is not much you can do but remove the limb. You can wait and see since the bees tunnel into dead wood, but it might be severely weakened with that much damage. Mimosa is a fairly short-lived tree, and you were lucky to have it as long as you did.
Your tree was probably being damaged for a couple of years. I doubt all that damage would have happened all of a sudden. Plants are resilient. Many of them can take quite a bit of abuse before they start showing it.
Bob Morris is a professor emeritus in horticulture with the University of Nevada and can be reached at firstname.lastname@example.org. Visit his blog at xtremehorticulture.blogspot.com. For more of his gardening advice, see the Home section of Thursday’s Las Vegas Review-Journal.