The school superintendent in Milton said five fifth-graders have been invited to Washington to help Michelle Obama plant the White House garden this spring. John Barone told the Burlington Free Press that he got the call from Obama Friday. School district officials said the call was prompted by the district’s changes to its food service. Obama had noted a blog post from Milton food service director Steve Marinelli about the fresh entrees now available to Milton students, along with fruits and vegetables in their new self-serve bars. The five students are being chosen based on essays they had written about Farm to School programs.