It is found in parts of Southern Europe and is hardier than the more familiar florist’s gladiolus. Cornflag is named for its habit of growing in grain fields where it is native; the corms produce numerous small cormels every year that make it difficult to eradicate. Cornflag is hardy in USDA hardiness zones 7 through 9. It is useful in the perennial border and is sometimes naturalized in rough turf areas in the South. You can find cornflag growing in the Dioscorides Garden and the Antique and Heritage Rose Garden in the National Herb Garden.