Fennel Flower Plant: What It Is and How to Grow It from Seed

Fennel flower (Foeniculum vulgare) is a perennial herb in the carrot family, native to the shores of the Mediterranean. The fennel plant grows up to 8 feet tall, has feathery leaves, and forms clusters of bright yellow flowers.

Every part of the fennel herb has a distinctive anise or licorice flavor and is used as a flavoring in cooking — particularly in dishes with fish. Fennel seeds are used for scenting soaps and perfumes and for flavoring candies, medicine, and food.

There are two types of fennel – herb and vegetable. The vegetable fennel is grown annually for its anise-flavored stalks and bulb-like base.

Fennel Flower Characteristics

About Herb Fennel

Fennel flower is a tender perennial, but it’s almost always grown as an annual herb. Herb fennel is cultivated worldwide for its edible dark green leaves and seeds. With a taste similar to licorice, fennel plants are used for medicinal purposes and as a flavoring in cooking.

All parts of the herb — including leaves, stalks, flowers, pollen, and seeds — are edible and used in many culinary traditions worldwide. Use fresh or dried fennel leaves in salads, coleslaws, soups, and stews. Use edible fennel flowers to garnish meat, fish, tomato, and potato dishes. Green fennel seeds are highly aromatic and are best used to enhance the flavor of stews and bread.

About Vegetable Fennel

The vegetable fennel (Foeniculum vulgare var. dulce) is called Florence fennel or finocchio. Florence fennel is a cool-weather crop, grown annually for its anise-flavored stalks and bulbous base. The plant’s thick stalks can be eaten raw or cooked, and its leaves, pollen, and seeds are used in cooking.

Although a member of the carrot family, the bulb fennel differs from the flower. Compared to sweet fennel, Florence fennel is shorter in height and grows up to 24 inches tall. With its fleshy stalks and feathery leaves, the stocky bulb looks more like celery than an herb.

How to Grow Vegetable Fennel

Florence fennel plants are grown from seeds. Start vegetable fennel seedlings indoors four to six weeks before the last frost date, or sow fennel seeds directly into the garden. Plant the seeds 8 to 12 inches apart and ¼ inch deep in rich, moist, and well-drained soil.

Vegetable fennel grows best in cooler temperatures. If planted earlier in the spring, these edible plants flower, reducing the bulb’s quality. The plant prefers uniformly moist soil. To keep the soil moist, irrigate with 1 to 2 inches of water per week throughout the growing season.

Young fennel plants mature in 60 to 90 days. When bulbs swell and become the size of an egg, mound soil around the bulb to help produce paler and mildly flavored fennel bulbs.

How to Grow Herb Fennel

Fennel flower is easily grown from seeds and requires little maintenance once established. These plants prefer a sunny location and rich soil. Herb fennel doesn’t transplant well due to its long tap root, and is best directly sown in the garden. Sow seeds directly in spring after the last frost date has passed.

Plant seeds about 4 to 6 inches apart and leave 18 inches between rows. When fennel flower seedlings have two sets of true leaves, thin the young plants to a distance of 12 to 18 inches apart. The flower is drought-tolerant and requires occasional watering once established, especially during the dryer summer months.

Fennel flower is a self-seeding plant and will readily re-seed if seedheads and faded flowers aren’t removed. A mature plant can produce up to 100,000 seeds, invading your entire herb garden.

Fennel Medicinal Uses

The fennel herb provides many health benefits and has been used for centuries in traditional medicine. The flowers are used to treat health conditions associated with reproductive, digestive, respiratory, and endocrine systems.

Fennel tea, powdered fennel, and fennel extract are beneficial for various ailments, such as bloating, intestinal gas, loss of appetite, colic in infants, coughs, and visual problems.

Fennel for Health

Both vegetable fennel and fennel seeds provide health benefits, contain many essential nutrients, and are low in calories. Vegetable fennel is high in fiber, vitamin C, and potassium.

Eating raw fennel provides other health benefits, including improved bone, skin, and eye health, lowered blood pressure, and decreased risk of heart disease.

Used to make essential oils, fennel seeds are full of antioxidants that lower the risk of chronic health problems such as obesity, cancer, heart disease, diabetes, and neurological issues.

Fennel Seeds

Fennel flowers produce tiny greenish-brown oblong seeds, which are also referred to as fruits. Consume green seeds or allow them to ripen and dry. Harvest the seeds by cutting the flower head once it turns brown.

Place the fennel flower heads in a paper bag in a well-ventilated room to dry. Store the dry seeds in an air-tight container and use them as a spice in recipes.

How to Deal With Invasive Herb Fennel

Unlike vegetable fennel, the herb fennel is considered an invasive species in some parts of the United States. The fennel flower changes the structure of many plant communities — taking light, nutrients, and water from native species.

To control invasive wild fennel, manually remove the flowers before they bloom and get a chance to re-seed. Burning mature plants and hand pulling small seedlings when soil is soft are effective control methods. If all else fails, use herbicides to deal with herb fennel’s invasive growth.

FAQs About Fennel

Here are some common questions about the fennel flower:

Are Dill and Fennel the Same Thing?

No, dill and fennel are two different plants used for different purposes. The main difference between dill and fennel is that all parts of the vegetable fennel are edible, while only dill’s leaves and seeds can be eaten. Fennel also has a distinctive licorice flavor that is absent in dill.

What Part of Fennel Is Used in Cooking?

The bulb is the most commonly used part of vegetable fennel in cooking, but the stalks and fronds can be cooked, too. Fennel bulbs can be roasted, caramelized, grilled, braised, or broiled. Use fennel stalks when making stocks, steamed seafood, or roast, and use fennel fronds in salads or as a garnish.

When Is Too Much Fennel Consumption?

Avoid eating more than 1 or 2 teaspoons of dried or whole fennel seeds daily. There is no recommended daily limit for how much fennel tea is safe to drink, so start with one cup at a time. Potential side effects of too much fennel include chest pain, nausea, vomiting, hives, rash, difficulty breathing, and itchy or swollen skin.