Without more details on what the symptoms are, I’d strongly suspect that the dreaded Red Bay Wilt may be the cause of this tree’s (Persea borbonia) decline. Here is a link to an article on this problem: http://okeechobee.ifas.ufl.edu/News%20columns/Red.Bay.htm
Red Bay Wilt is a systemic fungus that is spread by an ambrosia beetle. It was first reported in South Carolina in 2002. Red Bays in forested areas will probably be lost to an infection/infestation of this new pest complex. Dead trees and especially INFECTED FIREWOOD SHOULD NOT be moved off site to slow down the spread of this disease. Valuable shade trees in urban areas can be treated by professional arborists with a fungicide, but it is expensive and re-treatment will be needed. Closely related trees in the Laurel family, including sassafras and avocado, have also been reported to be hosts of this deadly wilt and exotic insect pest. Please check with your local County Extension Service office (http://www.csrees.usda.gov/Extension/index.html) for more information if the symptoms described in the article don’t match what you have observed.
