Supposed to kill ball moss but after two applications ball moss healthy as ever.
Expert response: Thank you for your comments! You may need to make a second application after 12 months to effectively kill ball or Spanish moss on Live Oak trees when used at the listed label rate. Keep in mind that killing the moss does not remove it from the tree, so you would still need to mechanically remove dead moss if it becomes an undesirable sight. This article from Texas A&M Forest Service has additional information about this plant: