Sorrel is a gourmet herb every garden deserves. It is a good source of potassium and vitamins A and C. Sorrel is known for its tangy and sour flavor. The lemon flavored leaves are used sparingly in salads or generously in soups and sauces. Sorrel is a perennial that is 16 to 24 inches tall with large, arrow-shaped leaves that can be picked individually from spring through fall. Sorrel produces some of the earliest greens of spring and the latest of fall. The tender, green leaves have an intense lemony flavor and should be harvested at 4 or 5 inches long. The leaves are often pureed for soups, or added to fresh salads.