Dill is a soft, annual plant with fernlike, feathery leaves and is similar in appearence to fennel leaves. Dill leaves are grown as an herb and the seed is harvested to be used as a spice. When grown as an herb, it is usually cut when it is 6 to 12 inches in height. Mature plants can reach 3 to 4 feet. Dill is said to have originated in Eastern Europe and has been cultivated all over the Mediterranean basin and Western Asia.