Vance H. Watson, interim president of Mississippi State University, stepped down after receiving heavy criticism for authorizing $12,333 in landscaping work last year at the home of Thomas C. Meredith, the state’s higher-education commissioner, the Chronicle of Higher Education reported. Meredith announced his retirement effective Nov. 15. State auditors ordered Watson to repay the university for the work, which included the planting of a dozen or more magnolia trees. Roy H. Ruby, a retired dean at the university, will serve as interim president.