Fennel and dill are similar plants with soft, feathery leaves and clusters of small yellow flowers in the umbels. Both plants are fragrant and carminatives that ease digestion. However, you can quickly tell them apart if you sniff or taste.
This guide will cover the key differences between dill and fennel plants and clarify why they are used for different purposes.
The main characteristics of dill and Fennel: Botanical classification
Dill and Fennel are two different herbs from the same plant family, Apiaceae. However, they belong to other genera and species that set them apart.
In Latin Anethum graveolens, dill is an annual herb native to North Africa, Iran, and the Arabian Peninsula. It has found widespread cultivation across Eurasia, where its leaves and seeds are used as a herbs or spices for flavoring food (1)
On the other hand, Fennel (Foeniculum vulgare) is a robust herbaceous perennial herb native to southern Europe and the Mediterranean and was probably cultivated by the ancient Greeks and Romans. (1)
While dill is only one, the genus Foeniculum vulgare includes three different groups:
- Florence fennel, cultivated for its bulb used in cooking;
- Sweet Fennel, grown for fresh leaves and sweet fruits – fennel seeds
- Bitter Fennel, cultivated for bitter-tasting fruits, is used mainly in cosmetics.
Dill and Fennel are both aromatic plants considered invasive or weedy and exceptionally easy to grow. They also attract butterflies.
Dill and Fennel: Difference in appearance
Although the dill leaves are very similar to those of Fennel, fern-like dill leaves are slightly wider and finely divided into thread-like segments, creating a lacy and airy structure.
Fennel leaves, also known as feathery fronds, have a similar dissected structure but a slightly different arrangement.
Fennel also produces thin leaves that are bright green, but they emit a distinct anise-like fragrance when crushed.
Their hollow stems, commonly known as umbellifers, have a similar appearance, but Fennel can grow up to 2 m tall, whereas dill can grow up to 40 – 150 cm.
Both members of the Apiaceae family produce small yellow flowers that bloom in clusters called umbels.
Dill seeds come from dried fruits 4–5 mm long, 1 mm thick, and have a straight to slightly curved shape with a ridged surface. Dried dill seeds are often used in pickling.
Fennel seeds, on the other hand, are twice as long as dill seeds and slightly curved. The fruit from which fennel seeds come is a dry schizocarp, measuring 4–10 mm long.
Though fennel fronds can be used in salads, the fennel bulb is the most commonly used part of the plant, while dill plants have no bulb. Fennel bulb is a versatile, mild veggie that is great sautéed or grilled in Mediterranean dishes or raw in salads.
If you are trying to identify Fennel, the white bulb at the base of the stem clearly distinguishes Fennel from other Apiaceae family members, like anise or the carrot plant.
Fennel vs dill: Flavor and Scent Distinction
Similar in appearance, dill and Fennel have a different flavor profile. Fennel has a highly distinct black licorice taste that is absent in dill. Dill shares the same faint sweetness as Fennel, but it has more of an herbal, grassy flavor.
Depending on their smell, you can quickly tell these plants apart, as dill has a more pungent aroma than Fennel, especially if you rub the leaves gently between your fingers.
Dill and Fennel may look like each other and share a licorice flavor, but I don’t recommend using Fennel as a substitute for dill as it tastes nothing like dill.
Dill vs Fennel: Can These Herbs Grow Together
Both dill and Fennel can be grown from seeds, but it’s recommended to plant dill seeds in spring and fennel seeds in the fall.
Dill thrives in cooler weather, making spring and fall the best seasons for planting. It tends to go to seed and die out in hot weather but can reappear if its seeds are left undisturbed. On the other hand, Fennel can grow throughout the year, even surviving mild winters. Regular pruning also helps control its size.
Plant both herbs in sunny to partially sunny locations, but avoid growing them too close together as they may cross-pollinate, affecting taste. If planting in the same garden, separate them with rows of other crops or use separate pots. Ensure the soil is rich in organic matter and well-draining. Hold off on fertilizing until the plants are well established. Cover the developing bulb with mulch or soil for Fennel grown for bulbs to maintain tenderness.
These two are widely used in kitchens worldwide for various culinary purposes. Fennel is versatile, with its entire plant used in cooking, whether raw or roasted, while dill is primarily an herb and garnish.
Dill is commonly used fresh in salads, dips, and sauces. Northern European cuisine uses dried dill leaves in soups, pasta, stews, and cooked dishes like gravlax. Dill is a key ingredient in making dill pickles.
Dill is a versatile herb that is best used fresh in salads, though freeze-dried leaves retain their flavor for a few months.
With a caraway-like flavor, the dill seed is used as a spice, and dill oil is extracted from various parts of the plant.
Wild fennel flowers, known as “fennel pollen,” are potent but expensive.
Dried fennel fruit is an aromatic spice with an anise-like flavor, best when green for cooking. Roasted fennel fruits are consumed as mukhwas or candied. Fennel seeds are included in paan, a popular breath freshener in parts of India.
The white bulb is crisp and can be sautéed, stewed, braised, grilled, or eaten raw. The Fennel shines in Mediterranean cuisines.
Florence fennel is one of the three main herbs used to prepare absinthe.
Young leaves add flavor to salads and garnishes, while leaf bases and shoots can be eaten like celery.