A herbicidal composition is provided comprising an aqueous solution of N-phosphonomethylglycine, predominantly in the form of the potassium salt thereof, at a concentration of at least 300 g a.e./l of the composition; and a surfactant component in solution or stable suspension, emulsion, or dispersion in the water, comprising one or more surfactants in a total amount of about 20 to about 300 g/l of the composition, wherein the composition has a viscosity of less than about 250 centipoise at 0° C. or a Gardner color value less than 10.