Celery seeds are harvested from celery plants after flowering and dehydrated to capture their earthy, bitter flavor, which, when used judiciously, enhances the foods they are paired with. Common food partners include tomato in Bloody Marys, cabbage in coleslaw, and root vegetables. They particularly shine as a background note in potato salad. Over the years, they have become a useful spice component in barbecue rubs and barbecue sauces.