Late spring and early summer applications of Milestone® on Canada thistle should be made after all plants have emerged and basal leaves are expanded. It is better to wait until some of the plants are at the bud growth stage to be sure that all plants are emerged before applying Milestone at 5 to 7 fluid ounces per acre (fl oz/A). Use the 7 fl oz/A rate at later growth stages. Canada thistle blooms at different times around the Western U.S., mainly due to elevation and moisture differences, so it is more important to plan applications based on the weed growth stage than the calendar. A summary of research work comparing Milestone to other herbicides for Canada thistle control is available online.
Applications of Milestone at 5 to 7 fl oz/A should be delayed until Russian knapweed has bolted and is in the early bud to flower stage through the fall, even after foliage has died from frost. It is important to remember that herbicide efficacy symptoms do not always show on Russian knapweed the season the treatment is made. The treated plants are dying and excellent control is achieved by the next growing season, so wait before making control evaluations. Milestone® has been evaluated extensively in university research trials and demonstration plots across the United States. Detailed information showing results of some of these field trials is available online.