Dill grows to 16–24 inches with slender stems and alternate, finely divided, softly delicate leaves 3.9–7.9 inches long. The leaves are threadlike and less than 1 mm broad. The flowers are white to yellow, in small umbels. The seeds are 4–5 mm long and 1 mm thick, and straight to slightly curved with a longitudinally ridged surface.
Fresh and dried dill leaves (sometimes called "dill weed" to distinguish it from dill seed) are widely used as herbs in for culinary purposes such as soups, pickles and fish. It is best when used fresh as it loses its flavor rapidly if dried; however, freeze-dried dill leaves retain their flavor relatively well for a few months.
In Santa Maria, Azores, dill is the most important ingredient of the traditional Holy Ghost soup (sopa do Espírito Santo). Dill is found practically everywhere in Santa Maria and is curiously rare in the other Azorean Islands.
Successful cultivation requires warm to hot summers with high sunshine levels; even partial shade will reduce the yield substantially. It also prefers rich, well drained soil. The seeds are viable for three to ten years. The seed is harvested by cutting the flower heads off the stalks when the seed is beginning to ripen. The seed heads are placed upside down in a paper bag and left in a warm, dry place for a week. The seeds then separate from the stems easily for storage in an airtight container.