Abstract: The invention provides a herbicidal composition comprising a mixture of: (a) polymeric microparticles containing a first herbicide, wherein the first herbicide is a synthetic auxin herbicide (e.g. dicamba, MCPA or 2,4-D) or an acetolactate synthase (ALS) inhibitor herbicide (e.g. triasulfuron, tribenuron-methyl, iodosulfuron-methyl, mesosulfuron-methyl, sulfosulfuron, flupyrsulfuron-methyl, or pyroxsulam); wherein the first herbicide, when in a salt-free form and when not contained within polymeric microparticles, antagonises the herbicidal activity of pinoxaden; and (b) pinoxaden; wherein the polymeric microparticles are controlled-release matrices, within which is the first herbicide, and which function in such a way as to control and/or slow down the release of the first herbicide from the polymeric microparticles into a liquid (e.g. aqueous) medium when the polymeric microparticles are placed (e.g. dispersed) in and in contact with the liquid medium.