Fennel

Fennel is a vegetable, spice, and herbal medicine all wrapped into one, offering a versatility that belies its invasive plant status.

Quick Facts
General Information
  • Common name(s)Fennel
  • Ayurvedic namesampf, methica
  • Scientific nameFoeniculum vulgare
  • Geographic distributionSouthern Europe, western Asia, North America, South America, New Zealand
  • Plant typeHerb
  • Native regionSouthern Europe, Western Asia
  • Main producer(s)India
  • Main Economic UseCulinary
Medicinal and Nutritional Information
  • Medicinal actionCarminative, Estrogenic
  • Key constituentsAnethole, coumarin
  • Ways to useCapsules, Food, Freshly ground
  • Medicinal rating(3) Reasonably useful plant
  • Safety rankingSafe
How to Consume
  • Edible partsFruit, Seed, Stem
  • TasteSweet
Growing
  • Life cycleAnnual
  • Harvested partsSeeds, Leaves, Stem, Bulb
  • Light requirementsFull sun
  • SoilLoamy sand
  • Soil pH7.4 – 7.8 (Slightly alkaline), 7.9 – 8.4 (Moderately alkaline)
  • Growing habitatTemperate climates
  • USDA Plant Hardiness Zones5a (From −28.9 °C (−20 °F) to −26.1 °C (−15 °F)), 5b (From −26.1 °C (−15 °F) to −23.3 °C (−10 °F)), 6a (From −23.3 °C (−10 °F) to −20.6 °C (−5 °F)), 6b (From −20.6 °C (−5 °F) to −17.8 °C (0 °F)), 7a (From −17.8 °C (0 °F) to −15 °C (5 °F)), 7b (From −15 °C (5 °F) to −12.2 °C (10 °F)), 8a (From −12.2 °C (10 °F) to −9.4 °C (15 °F)), 8b (From −9.4 °C (15 °F) to −6.7 °C (20 °F)), 9a (From −6.7 °C (20 °F) to −3.9 °C (25 °F)), 9b (From −3.9 °C (25 °F) to −1.1 °C (30 °F)), 10a (From −1.1 °C (30 °F) to +1.7 °C (35 °F)), 10b (From +1.7 °C (35 °F) to +4.4 °C (40 °F))
  • Potential insect pestsAnts
Additional Information
  • Other usesRepellent
Fennel

Fennel may now be a familiar sight on coastlines and plains across the world, but the abundant plant should not be misconstrued as common: behind it is a history of human use that spans from stem to seed to flower, with a flavorful aroma that has lent itself to culinary feats for centuries and a list of medicinal benefits that is lengthy, to say the least. Particularly hallowed in Italy and Greece, fennel is native to the shores of the Mediterranean, though it has since been naturalized in northern Europe, Asia, North America, and Australia. In the latter two, it is now considered an invasive weed.

Medicinal and Nutritional Information

Quick Facts (Medicinal and Nutritional Information)
  • Medicinal actionCarminative, Estrogenic
  • Key constituentsAnethole, coumarin
  • Ways to useCapsules, Food, Freshly ground
  • Medicinal rating(3) Reasonably useful plant
  • Safety rankingSafe

Health Benefits of Fennel

Fennel has been used for many different purposes throughout history, most importantly for:

  • Restoring hormonal balance. Fennel stimulates the production of estrogen in the body, thus helping relieve premenstrual syndrome (PMS) and menopause symptoms.

  • Promoting digestion. The carminative properties of fennel aid digestion, preventing abdominal bloating and gas. 

Additionally, the active compounds in fennel help lower high blood pressure, and the herb has been traditionally used for treating infant colic and respiratory problems.

How It Works

Fennel has two main active ingredients: anethole, which provides antimicrobial and antifungal power, and coumarin, which suppresses appetite in the short term. The seeds in particular are high in phytoestrogens. Additionally, fennel is valuable not only for vitamins and minerals, but for other properties as well. One cup (87 g) of raw fennel contains 10% of the average daily requirement for dietary fiber and has high concentrations of potassium, manganese, vitamin B9 (folate), and vitamin C (ascorbic acid).

Herbal medicine has long used fennel for eye conditions such as glaucoma, and scientific research supports its potential in this area, but the plant is most widely used today as a carminative and expectorant, relieving gas and other digestive issues like stomach pain and bloating. Menopausal women particularly benefit from its consumption, as its phytoestrogenic elements can help replace dwindling estrogen levels, thus reducing the unpleasant side effects of hormone imbalance.

Some research suggests that fennel may be effective in treating hypertension and aiding weight loss.

Other herbs with carminative properties are cloves and rosemary, while anise and dong quai also have estrogenic actions.

Fennel Side Effects

Fennel seeds are toxic in large doses, so the suggested dosage should not be exceeded. Fennel essential oil should never be taken orally and must be properly diluted before topical application. Pregnant women, breastfeeding women, and small children should not take medicinal preparations of fennel.

How to Consume Fennel

Quick Facts (How to Consume)
  • Edible partsFruit, Seed, Stem
  • TasteSweet

The best way to reap fennel's health benefits is consuming the herb in medicinal forms. Medicinal preparations are typically made from the seeds or fruits. However, all parts of the plant are edible. They have a crisp texture and sometimes licorice-like taste, and are used for culinary purposes.

Remedies

Main preparations: Capsules, essential oil, infusion, syrup

While capsules are available commercially and make easier to manage dosage and intake levels, infusions and syrups can be made at home. Fennel's essential oil, though rarely used, must be properly diluted before application.

Food

Main ways: Fresh, dried

The hollow stems and leaves of fennel are commonly eaten raw in salads, especially in Italy. For some, however, the taste can be too pungent on its own.

Dried seeds are most commonly employed for seasoning in larger dishes, though they are sometimes eaten raw. The bulb and leaves are sautéed, stewed, or grilled as a side in mainstay dishes.

Culinary traditions throughout Europe and Asia have taken to its inclusion in seafood and rice dishes, as well as in spice blends for meat marinades.

Fennel is also featured in Middle Eastern foods as an aromatic element, and many parts of India and Pakistan are known to roast the seeds to freshen breath after meals. Its flowers are the most potent and expensive part of the herb, and they are best known for their use in making a liquor called absinthe.

Buying

Fresh and Dried Fennel

In culinary terms, fennel is generally considered a fall and winter vegetable, and fresh versions of the plant may be easier to find at farmers' markets and grocery stores during these seasons. The dried fennel seed, however, is a common seasoning found in major supermarkets worldwide throughout the year. To grow the plant for the benefit of all its parts, whole specimens can be found in garden stores during cultivation seasons.

Fennel Supplements

Fennel supplements can be found in many specialized health food stores, as well as through some wholesale retailers and several different outlets online. Often, they are found as a seed extract, as this part of the herb contains higher concentrations of its medicinal elements. Capsules are also widely available.

Growing

Quick Facts (Growing)
  • Life cycleAnnual
  • Harvested partsSeeds, Leaves, Stem, Bulb
  • Light requirementsFull sun
  • SoilLoamy sand
  • Soil pH7.4 – 7.8 (Slightly alkaline), 7.9 – 8.4 (Moderately alkaline)
  • Growing habitatTemperate climates
  • USDA Plant Hardiness Zones5a (From −28.9 °C (−20 °F) to −26.1 °C (−15 °F)), 5b (From −26.1 °C (−15 °F) to −23.3 °C (−10 °F)), 6a (From −23.3 °C (−10 °F) to −20.6 °C (−5 °F)), 6b (From −20.6 °C (−5 °F) to −17.8 °C (0 °F)), 7a (From −17.8 °C (0 °F) to −15 °C (5 °F)), 7b (From −15 °C (5 °F) to −12.2 °C (10 °F)), 8a (From −12.2 °C (10 °F) to −9.4 °C (15 °F)), 8b (From −9.4 °C (15 °F) to −6.7 °C (20 °F)), 9a (From −6.7 °C (20 °F) to −3.9 °C (25 °F)), 9b (From −3.9 °C (25 °F) to −1.1 °C (30 °F)), 10a (From −1.1 °C (30 °F) to +1.7 °C (35 °F)), 10b (From +1.7 °C (35 °F) to +4.4 °C (40 °F))
  • Potential insect pestsAnts

Fennel is an annual favorite among amateur gardeners for its easy and rapid cultivation. However, it is recommended not to plant fennel alongside species like tomatoes and beans, as fennel may inhibit their growth.

When left on its own, fennel will grow as a perennial, but it is cultivated as an annual, since harvesting it ends the plant's life cycle.

Growing Guidelines

  • Because of its invasive nature, many prefer to isolate growth to specific areas. Full sun is preferable, but some shade is advised in the hottest months of summer.

  • Seeds should be planted after the last frost, 10 inches (25 cm) apart to avoid damaging transplants and competition between plants. 

  • Though it is ultimately a cold-weather herb, germination requires temperatures between 65 - 70°F (18 - 21°C)

  • Harvesting is possible approximately 12 weeks after planting, when the bulb is about the size of a tennis ball.

Additional Information

Quick Facts (Additional Information)
  • Other usesRepellent

Plant Biology

The plant stands an average of five feet (1.5 m) tall on hollow stems and has fine, feathery leaves. Yellow flowers are produced on a single umbel, or rib-like structure that radiates from a single point. Small seeds are ovular and grooved. The plant is easily mistaken for poison hemlock, which can be dangerous for those harvesting from the wild.

  • Classification

    Fennel is a member of the large Apiaceae botanical group, and one of the 3,700 species comprised within this family of aromatic plants, boasting close ties with anise (Pimpinella anisum), carrot (Daucus carota), and celery (Apium graveolens).
  • Varieties and Subspecies of Fennel

    There are several different cultivars of fennel, but two main groups exist in widespread cultivation. Florence fennel (Foeniculum vulgare var. azoricum) is the most populous and widely cultivated, recognizable for its sweet, aromatic flavor that is similar to anise, though stronger in scent. Its counterpart, bronze-leaved fennel, is used more frequently as a decorative or ornamental plant, as opposed to a food product or herbal medicine.

Historical Information

The first written records of fennel belong to the ancient Roman historian Pliny, who lived from 23 - 79 BCE and credited the plant as an herbal remedy for 22 different conditions. The plant was likely plentiful long beforehand, however, as the ancient Greeks featured it in mythological tales and were later known to call it marathon due to its wild growth on the field where the famous battle of Marathon was fought. The Middle Ages saw the herb's migration throughout Europe as an appetite suppressant and fighter of evil spirits, and it was brought west with Puritan pilgrims for religious fasting purposes.

Economic Data

Despite its prevalence in the wild, fennel is also cultivated as a spice crop in many parts of the world, chiefly for its seeds and essential oils, which are used in several different industries. India is responsible for the majority of the world's fennel production, having generated over 58,000 tons in 2011. Most of this is consumed within the subcontinent itself, but the fraction that is exported still results in $10.7 million USD per year. Other countries with high yields include Turkey, France, and Germany.

Other Uses

  • For gardening. Fennel's primary uses remain nutritional, but it is also grown widely as an ornamental element in temperate-climate gardens for its bright color and sweet fragrance.
  • For repelling insects. The plant is thought to be disliked by fleas, and a powdered version of the herb is sometimes used as a preventative home remedy for keeping the insects away from domesticated animals.

Bibliography