Flavorful foliage brings a mild, pleasing mustard taste to salads, soups, stir-fry or used as greens. Leaves are also quite attractive, in shades of bright green or deep burgundy, perfect for the edible landscape or simply ornamental use. Mustard is a cool-season vegetable that can turn bitter in the heat of summer; for best quality greens, plant in early spring and again in fall, avoiding hot weather. A quick, easy-to-grow vegetable. Plants are biennial, but should be pulled after the first season because second year plants are not attractive and foliage turns bitter when flowers form.