The present invention relates to a solid herbicidal composition comprising: i. mesotrione ii. at least one arene sulfonate condensed with formaldehyde (e.g sodium alkylnaphthalene sulfonate condensed with formaldehyde) and iii. an acidifying agent. The present invention further provides a method of controlling weeds at a locus comprising diluting the solid herbicidal composition of the present invention and applying to the locus a weed controlling amount of the diluted herbicidal composition.