Dill is an erect, freely branching annual herb with finely dissected, lacy, blue-green foliage. "Dill weed" refers to the foliage, and the seeds are usually just called "dill." The leaves are about 1 ft (0.3 m) long and divided pinnately, three or four times into threadlike segments each about 1 in (2.5 cm) long. The dill plant grows about 3-5 ft (0.9-1.5 m) tall and sometimes gets top heavy and falls over. The flowers are yellow and borne in large, rounded, compound umbels (umbrella-like clusters in which all the flower stems originate from the same point) on stiff, hollow stems. The whole inflorescence can be 10 in (25 cm) across, and several of them on a feathery blue-green framework can be showy indeed. The fruit is a flattened pod about an eighth of 1 in (2.5 cm) long. All parts of the dill plant are strongly aromatic. Dill does best in full sun; it becomes leggy and prone to topple over in partial shade. Dill does best in well-drained soil with typical garden watering. It may bolt quickly to flower during a prolonged dry spell.
Anethum graveolens (dill) - Floridata, http://www.floridata.com/Plants/Apiaceae/Anethum%20graveolens/674 (accessed January 27, 2017).