Learn how to grow fennel in minutes. Fennel can be grown for its leaves, stems, flowers, and seeds. Common fennel is grown as an herb. Its leaves and seeds are used in cooking and baking. Florence fennel—which has a bulbous stem and is a variety of common fennel– is grown for its stem which is eaten as a vegetable. The leaves of common fennel are feathery with a licorice-like flavor. They can be added raw to salads and vegetables. The seeds of common fennel are often added to stuffing and apple pie.

Get to Know Fennel

  • Botanical name and family: Foeniculum vulgare (common fennel); Florence fennel is a cultivar of common fennel; it forms a bulb at the base of the stem; the botanical name of Florence fennel is Foeniculum vulgare azoricum.
  • Mediterranean
  • Type of plant: Fennel is an herbaceous perennial commonly grown as an annual.
  • Growing season: Summer
  • Growing zones: Zone 6 to 10
  • Hardiness: Fennel is heat tolerant but just slightly cold-tolerant; it will survive a frost but will die to the ground when freezing weather arrives.
  • Plant form and size: Fennel grows in clumps with numerous vertical stems from 5 to 7 feet tall; each stem branches near the top and each branch ends with a flat-topped cluster of small yellow flowers; fennel looks very much like dill but is taller and more coarse. Florence fennel is lower growing; it has a large thick stem or leaf base which is bulb-like. The bulb can be eaten as a vegetable and is often called finochio.
  • Flowers: Fennel has flat clusters of yellow flowers that grow in clusters or umbles at the ends of the stems above the foliage.
  • Bloom time: Fennel blooms from mid-summer to frost.
  • Leaves: Fennel has bright yellow-green leaves that are intricately divided, almost threadlike; they resemble dill leaves. Fennel leaves grow on upright, hollow, fleshy stems to about 5 feet tall.

How to Plant Fennel

  • Best location: Plant fennel in full sun.
  • Soil preparation: Plant fennel in well-drained compost-rich soil, however, fennel will grow in all types of soil. Fennel prefers a soil pH of 6.0 to 6.7.
  • Seed starting indoors: Fennel grows a taproot and is best sown in place. If started indoors, plant in individual peat pots so that taproots are not disturbed at transplanting. Sow seed indoors 6 to 8 weeks before the last frost.
  • Transplanting to the garden: Set fennel in the garden after the last frost in spring.
  • Outdoor planting time: Sow common fennel seed in spring as early as 2 to 3 weeks before the average last frost date. You can also sow fennel in late summer or early fall for harvest before the first frost. Fennel is half-hardy and will tolerate a light frost. Make succession plantings through late summer for harvest into autumn
  • Planting depth: Sow fennel seed ⅛ to ½ inch deep. Seeds must be covered completely to germinate.
  • Spacing: Space fennel plants 10 to 12 inches apart. Space rows 2 to 3 feet apart. Fennel re-seeds itself readily; plant it where it can grow for several seasons.
  • How much to plant: Grow 1 to 2 fennel plants for cooking; grow 4 to 5 plants for preserving.
  • Companion planting: Grow fennel with sunflowers, calendulas, and nasturtiums to attract butterflies, hummingbirds, and beneficial insects to the garden. Fennel is said to interfere with the growth of beans, tomatoes, and kohlrabi. Do not plant fennel near dill or cilantro; they may cross-pollinate.

How to Grow Fennel

  • Watering: Give fennel regular, even watering until it is established. Once established, fennel can be kept on the dry side. Do not overwater fennel.
  • Feeding: Side dress fennel with aged compost at midseason.
  • Mulching: Mulch around fennel in summer to keep roots cool. To make bulb fennel tastier, mulch around the base of the plant to blanch the bulb and make it tender.
  • Care: Common fennel can grow 4 to 5 feet tall and may require staking or supports, especially if it is growing in a windy spot. Mound soil up around the base of Florence fennel to blanch the bulb and make it tender.
  • Container growing: Common fennel will grow easily in a container. Choose a container at least 12 inches deep; fennel forms a taproot so the container must be deep enough for the root.
  • Winter growing: Fennel can be grown outdoors in mild winter regions.

Troubleshooting Fennel

  • Pests: Fennel is a member of the parsley family. Parsley caterpillars may attack fennel. Remove caterpillars by hand.
  • Diseases: Root rot can be a problem if fennel is overwatered or planted in soil that is not well-drained.

How to Harvest Fennel

  • When to harvest: Fennel leaves can be snipped for fresh use once plants are 6 inches tall or more and established. Snip leaves before flowering. Common fennel will reach maturity in 60 to 70 days. Harvest the seeds of common fennel after flowering when they turn brown. The thick bulbs at the base of Florence fennel can be eaten like a vegetable as soon as it is large enough to eat; peak flavor of the bulb comes after flower buds have formed but before blossoms begin to open. Harvest seeds when they turn from yellowish-green to brown. If you do not want seeds, snip away flowers as they form.
  • How to harvest: Use snips or scissors to harvest leaves. Cut only the top 2 or 3 inches to ensure regrow.

Fennel in the Kitchen

  • Flavor and aroma: Fennel leaves and seeds have a pleasant licorice-like flavor.
  • Leaves: Use fresh leaves in salads and with vegetables, fish, pork, eggs, and rice. Young leaves are milder and sweeter than older fronds.
  • Stems: Fresh stalks can be eaten like celery. Use stems in salads or soups. They have a nutty
  • Bulbs: Harvest the bulb of Florence fennel while still tender, just before flowering. Eat it raw or cooked as a vegetable. Use bulb fennel in soups and pasta dishes. Slice the bulb thinly and add to salads. The bulb can be cooked in gratins, sautés, and casseroles.
  • Flowers: Fennel flowers are edible and can be added to salads.
  • Seeds: Use fennel seeds in home-baked bread, cakes, cookies, sausage, and beverages. Use seeds with cheese spreads, salad dressings.

Preserving and Storing Fennel

  • Refrigeration: Keep fresh fennel in a plastic bag in the refrigerator crisper; use fennel within three days.
  • Drying: To collect fennel seeds, cut the seed head and put it in a paper bag in a warm dry place; seeds will drop into the bag as they ripen and dry.
  • Freezing: Chop and freeze the leaves in a zippered bag for later use.
  • Storing: Dried leaves and seeds can be stored in an airtight jar.

Propagating Fennel

  • Seed: Grow fennel from seed that has been stratified (chilled or frozen) for at least 2 weeks. Direct sow seed in the garden any time of the growing season. Seeds sprout in 14 days.

Fennel Varieties to Grow

  • Florence fennel(Foeniculum vulgare azoricum), also called, finocchio, is grown primarily for its stems and bulbous base which can be used as a vegetable.
  • Bronze fennel( F. v. rubrum) has bronzy purple new growth that lightens to bronze in midsummer. Bronze fennel is grown as an herb and ornamental plant.

Also of interest:

How to Grow Florence Fennel

How to Grow Mint

How to Grow Thyme

How to Grow Oregano

How to Grow Parsley

How to Start a Herb Garden

Growing Herbs for Cooking

Fennel Seeds – Florence Fennel Herb Seed

Herb Specifications

Season: Annual

USDA Zones: 3 – 9

Height: 24 – 60 inches

Bloom Season: Summer

Bloom Color: Yellow

Environment: Full sun

Soil Type: Well-drained, pH 6.1 -7.5

Planting Directions

Temperature: 50 – 70F

Average Germ Time: 12 – 18 days

Light Required: No

Depth: 1/4 inch

Sowing Rate: 1 seed every 2 – 4 inches

Moisture: Keep moist until germination

Plant Spacing: Rows 24 inches a part; thin seedlings 8 – 12 inches

Fennel (Foeniculum Vulgare Florence) – All parts of this herb are aromatic and delicious! The bulb, foliage, and herb seeds of the Fennel plant are widely used in many of the culinary traditions of the world. Sweet Fennel is widely cultivated, both in its native range and elsewhere, for its edible, strongly-flavored leaves and Fennel seeds. The flavor is similar to that of anise, though usually not so strong and more aromatic and sweeter.

All parts of Fennel herb plants are aromatic, imparting a sweet anise, or licorice, scent and flavor. Kids – or adults – who like black licorice will love chomping on the raw bulbs of fennel! Growing to 60 inches tall and 24 inches wide, Florence Fennel is topped by erect, hollow stems with pale yellow flower umbels.

Harvest can take place usually 100 days after sowing the Fennel seeds. Bulbs can be pulled and eaten as a vegetable or Florence Fennel seed can be collected as the umbels dry and turn brown in color. Cover the seed head with cloth or a bag, cut the stems and catch the herb seeds that are disturbed in the cloth or bag. The Fennel seeds pop out easily.

How to Grow Florence Fennel From Herb Seed: Grow in rich, light soil in a warm location and provide ample water so that the bulbs will form properly. Sow the herb seeds directly in the garden as soon as ground can be worked.

Approximate Seeds Per Ounce: 4,000

Grow fennel: plant, care, varieties and harvest

NEIL ROSS / NZ GARDENER Fennel flowers are landing pads for beneficial bugs.

As a dreamy, emo teenager schooling myself on herbs, I was thrilled by the ominous words of a 13th-century physician that “He who sees fennel and gathers it not, is not a man but a devil.” I’d never heard of fennel, but the words were satisfyingly edgy.

I copied them out in my best copperplate on a piece of paper and attached them to my wardrobe door.

What the physician was referring to in his overdramatic way was fennel’s use for treating a range of maladies, such as digestive and menstrual issues, to increase breastmilk and relieve colic in babies.

SALLY TAGG / NZ GARDENER Cultivated fennel.

My motivation for growing fennel right now is so I can try and recreate a shaved fennel and apple salad with white bean hummus and pickled raisins that I order every time I go to Al Brown’s Federal Delicatessen.

The fennel used in this dish is the stocky white base of bulbous Florence fennel (Foeniculum vulgare azoricum), a cultivar of leaf fennel (Foeniculum vulgare), which grows wild in many parts of the country.

* Save your own seeds: Seed-saving basics & choosing what to save
* How to grow onions
* How to grow cabbages

123RF Bronze fennel.

Fennel is easily grown from seed sown direct or in pots. It can be grown throughout New Zealand and is best sown from seed in early spring when soil is warming up but it’s not too hot. In tropical to temperate areas it can also be sown from early to mid-autumn.

Plant it in full sun in free-draining, well-tilled soil and cover lightly. If you want to harvest your fennel sooner or live in a colder area, buy established plants.

Florence fennel grows best in an alkaline soil so add lime before planting. Keep it well-watered to avoid woody stems. As the bulbous base begins to swell, mound up the soil around it to keep it upright and white.

If you’re growing wild fennel you’ll only need one or two plants as they quickly produce loads of leaves and can reach 2m when flowering. The umbelliferous yellow flowers look fantastic in flower arrangements.


‘Finale’ from Kings Seeds, is a bolt-resistant variety of Florence fennel suitable for year-round sowing.

Add burnished tones to your garden with Foeniculum vulgare ‘Purpureum’, a bronze variety of wild fennel (Kahikatea Farm).

123RF Florence fennel. Fruits, veges and herbs you can plant to feed the bees AND your family.

Fennel bulbs can be harvested from the size of hens’ eggs right up to fist-size or bigger. However, smaller bulbs are generally the sweetest. They’ll be ready to harvest in around 90 days (don’t wait too long as they’ll go woody).

If you cut off the bulb above the ground new bulbs will grow from side shoots.

The feathery fronds of Florence and leaf fennel can be added to a range of dishes from fish to pork to salads. Don’t add too much as the flavour can overpower a dish.

123RF Fennel seeds.

Seed from the dried flowerheads can also be collected, dried and used to add flavour to dishes.

NZ Gardener

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Fennel is a plant for which the roots are the part we eat and its nutritious and culinary value is exceptional. It is a very good summer vegetable.

Foremost fennel facts

Name – Foeniculum dulce
Family – Apiaceae (parsley family)
Type – biennial
Height – 16 to 24 inches (40 to 60 cm)
Exposure – full sun
Soil – ordinary to rich
Harvest – July to December, 3 months after sowing

Planting, sowing fennel

It is a good idea to sow in a sheltered place starting from the month of March and April and up till the month of July.

Fennel loves rather light, rich and relatively cool soil.

  • Favor sowing in a nursery if you’re sowing in March and April or sow directly in the plot during the month of May.
  • Dig furrows 2 inches (5 cm) deep every 8 to 10 inches (20 to 25 cm).
  • Cover seeds with ½ inch (1 cm) soil.
  • Keep the soil mix a little moist and water regularly using a gentle drizzle after sprouting.
  • Once the first leaves have sprouted from the ground, thin down to about 8 inches (20 cm).
  • Transplant to the vegetable patch after the last frost spells, starting from the month of May.

It helps to enrich the soil with manure-based fertilizer in order to enhance growth.

  • It also is a good practice to ridge your plants as they grow, so that you may blanch their bulbs as you would leek.
  • Stop ridging when the ridge is 4 to 6 inches (10 to 15 cm) tall.

Harvesting and keeping fennel

There are actually two parts of the plant that can be collected. Most common is to eat the head of fennel as a vegetable.

You can collect your fennel whenever you need it, depending on how large the heads have become.

Once the first frosts have hit, pull all your fennel out and keep it in a cool, ventilated and rather dark place.

The best way to keep your fennel is to store them in a cellar in crates filled with sand. If you haven’t any cellar, freeze them in a freezer.

But fennel seeds are also delicious and can be used in cooking just like cumin or aniseed.

Learn more about fennel

An excellent vegetable known for its nutritious value as well as its digestive and antioxidant properties, fennel is an admirable addition to most of the summer dishes you can prepare, and its aniseed-like flavor will enchant you.

So the health benefits of fennel are well acknowledged, and fennel is delicious when integrated into culinary recipes with its light taste of aniseed.

Although the Mediterranean diet is where it is most present, fennel is grown more or less everywhere in mild climate regions.

Also, remember not to confuse fennel with dill because even though the two plants look alike and that dill is sometimes called the “bastard fennel”, they are quite different. Likewise, although the taste is very similar to that of aniseed, the leaves which are very different will help you tell them apart.

Smart tip about fennel

Collect all the small grains of that appear at the end of the small yellow flowers and add them to your ‘Fleur de sel’ fine table salt.

They will flavor your dishes, especially your fish meals.

Read also:

  • More about growing herbs
  • Health benefits of fennel
  • Aniseed, often confused with dill and fennel

Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Fennel growing by Valerie Becker under © CC BY-NC 2.0
Fennel seeds by flomo001 under license
Fennel heads by Cornelia Gerhardt under license
Fennel flowers by Sabine under license

How to grow fennel

An alotment in Bournemouth with a good crop of fennel (left); fennel bulbs ready for harvest (right).

Some vegetables deserve to be more popular than they are, and Florence fennel is certainly one of them. A defining ingredient in Italian cooking, it is a gourmet’s treat that is prized mainly for the engorged bulbs that form just above the soil surface.

Like the proverbial elephant described by blind men, the bulbs produced by fennel are the sum of quite unrelated parts. Anatomically, they are formed from the thickened, overlapping bases of leaves and have the same layered construction of an onion. The texture is crunchy and stringy like celery, and the flavour is similar to that of anise or licorice. Somehow, defying all logic, the differences are magically reconciled to create a desirable vegetable of sublime elegance.

A growing concern

Fennel is closely related to carrots, and like them, its seeds are very slow to germinate.

Fennel seed is slow to germinate.

Given this idiosyncrasy, a crop is easier to establish from transplanted seedlings rather than from seed sown directly into the ground. To produce transplants, just sow seed in compost-filled module trays from March to July.

Fennel is best started by sowing into modules and transplanting the seedling when the roots have filled the cell.

Pest and weed problems associated with crop establishment are then avoided, and the only thing that remains is keeping the compost moist at all times. Transplanting can commence five weeks or so after sowing, when the roots have filled the cells and the seedlings are about 10cm tall.

Fennel seedlings can normally be transplanted about five weeks after sowing.

When they are transferred to the ground, leave about 20 cm between seedlings each way and dose them with water to settle the soil around the roots.

Fennel should be planted about 20 cm apart.

Other than the usual troika of pests – slugs, snails and rabbits – fennel is remarkably trouble free. Once the pests are under control, all you then need to do is follow two essential rules: keep the soil moist and maintain weed control. Bolting can be a problem, especialy with early sowings made when temperatures are low. Avoid disturbing the roots when transplanting seedlings, and keep the plants well-watered throughout their lives. Some varieties are prone to bolting, so choose those with more resistance.

Italian gardeners living in England ridge soil around the bulbs to blanch them, and if you want to do the same, wait until they put on some size and swell up before commencing. Blanching, however, isn’t really necessary, and personally, I think it involves way too much work.

Some gardeners put soil around the bulb to blanch their fennel, but this is not necessary as the bulbs will naturally produce white flesh.

Harvesting can begin once the bulbs are about 8 to 10 cm in diameter. A quick and brutal method is to pull the bulbs up for a once-off harvest of each plant.

Fennel var. Rondo bulbs harvested by being pulled up.

My favourite way, however, gives two crops from the same plant and involves slicing through the bottom of the bulb with a sharp knife, leaving a small, flat stump about 6mm thick.

Fennel bulbs harvested by slicing through the bottom of the bulb with a sharp knife.

If done correctly, new plants will sprout from the stump, yielding a crop of baby bulbs.

Regrowth from an old fennel root.

Cooking up a storm

After the plants are harvested, trim off the tops and eat the bulbs raw in a mixed salad or on their own thinly sliced and simply dressed with lemon and olive oil. Alternatively, cut the bulbs in half lengthwise and braise them in water with either olive oil or butter. Heaven.

Under no circumstances should you let the rest of the plant go to waste. The tall, thin stems just above the bulbs can be cut up and thrown into soups and gravies to add extra flavour – they are quite tough, so remember to remove them before serving. The fine leaves topping the stems are a particular treat either chopped up and sprinkled over cooked vegetables and pork chops or added to a tomato-based pasta sauce just before serving. The anise flavour is real plus that lifts dishes to a new level.

Because Florence fennel is not especially popular, don’t expect to find a huge number of varieties in seed catalogues. Despite the limited choice, however, there are some decent ones worth tracking down, such as Rondo, a modern hybrid that is very bolt resistent, reliably producing fat, rounded bulbs of exceptional quality. Another fairly good one is the non-hybrid Zefa Fino, with bulbs that are somewhat flattened and seeds that are relatively inexpensive.

The variety Rondo produces very high quality, fat, rounded bulbs.

Once watering and weeding are sorted, Florence fennel is easy to grow and great to eat. Two harvests are possible from the same sowing, and nothing goes to waste. With so much going for it, it’s a puzzle why fennel isn’t more popular.

© Michael Michaud

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