The dill plant (Anethum graveolens) is an aromatic annual herb in the carrot family (Apiaceae). It is widely cultivated for its foliage, often called dill weed, and its seeds, which are used as a spice. Characterized by a strong, distinctive scent, dill is popular worldwide for flavoring pickles, fish, and soups. Its appearance shifts dramatically throughout the growing season, moving from a delicate, feathery form to a tall, flowering structure.
Vegetative Appearance (Foliage and Stem)
The foliage provides a delicate, airy texture and is highly aromatic. The leaves are a distinctive bluish-green or dark green color. They are deeply divided and pinnately compound, finely cut into soft, thread-like segments that create a fern-like appearance. This wispy structure is the source of the common name “dill weed” and is the part most frequently harvested for fresh use.
The fine foliage is supported by a single, upright main stalk that is slender and generally light green. This primary stem is hollow and smooth, sometimes showing white vertical striations. Leaves attach alternately along the stalk, which branches out as the plant matures. Although stiff, the stem’s delicate nature makes it susceptible to damage from strong wind or heavy rain.
Flowering and Seed Head Structure
As the plant matures, usually around mid-summer, it produces a long flower stalk, transitioning to its reproductive stage. The flowers are small, numerous, and bright or golden-yellow. These blooms are arranged in large, flat-topped clusters called umbels.
The umbel is a defining characteristic of the Apiaceae family, where flower stems radiate from a single point. Dill’s compound umbels can be quite large, sometimes reaching ten inches in diameter, and attract beneficial insects. After pollination, the umbels dry out, and the plant forms its fruit, commonly referred to as dill seeds. These seeds are small, oval, and flattened, transitioning from vibrant green to light brown or tan as they mature. The surface of the seed is marked by distinct longitudinal ridges, and the weight of the developing seeds often causes the tall, slender stems to droop slightly.
Size, Growth Habit, and Root System
Dill is an annual with an upright, spindly growth habit, often reaching a substantial mature height. Most varieties grow between two and four feet tall, though some cultivars can reach up to five feet. The plant’s spread is moderate, typically ranging from two to three feet wide, and it tends to look sparse or lanky compared to bushier herbs.
Due to its height and slender stem structure, taller dill plants may require external support, such as staking, especially when seed heads are heavy. This upright growth is anchored by a significant root system. Dill develops a long, slender taproot, similar to a carrot, which dives deep into the soil for stability. Because this taproot is sensitive to disturbance, dill is generally sown directly into the garden rather than being transplanted.