Mix salt, ginger, nutmeg, allspice, cinnamon, and cloves in a small bowl and reserve.
Take out and throw away neck and giblets from capon. Wash and dry capon and cut off any extra fat. Beginning at the neck cavity, release skin from breast and drumsticks by inserting fingers and gently separating skin and against the meat. Massage the spice mixture between skin and meat.
Arrange capon on a vertical roasting rack in a baking pan. Bake for 15 minutes on lower rack of oven. Lower oven temperature to 400 degrees F and roast 1 hour or until a meat thermometer reads at least 185 degrees F. Tent with aluminum foil and let rest 15 minutes before serving. Take off skin before serving.