John from Hawaii writes
Casoron 4G Herbicide is labeled for use on a number of ornamentals including azalea, boxwood, lilac, holly, etc. It is not specifically labeled for use on bougainvillea. You may want to contact the manufacturer directly to see if they would recommend it for this use. OHP Inc. can be reached at 800-659-6745.
Answer last updated on: 11/01/2018