Branch Dieback in Citrus (Orange)

Q. I have a ‘Eureka’ lemon tree with a branch or two that are dying. Is this borers?

Lemon tree with single branch dying back.

A. Probably not borers but a disease. Look for sap near the location where the branch died.

Single Branch Dieback of Lemon Most Likely Shoot and Twig Dieback Disease

Branch dieback in citrus, particularly lemon, is very confusing. It is not likely to be a borer problem. Most likely it is a disease issue called “shoot and twig dieback” of citrus. A lot of federal funding went to California to answer a branch dieback disease questions for homeowners and commercial growers, with lemon branch dieback found to be quite common.

            If it were me, I would cut the dead branches back and eliminate the dead branch to a place where it was healthy and growing in the direction I wanted. As a precaution, I would sanitize the pruning shears with undiluted 70-90% ethyl alcohol before and after each branch removal. Treat the fresh cuts with copper sulfate (Bordeaux mix) as a precaution.