What Is Fennel? Everything to Know and Love About This Fragrant Plant

Makenna Held, the author of Mostly French and a cooking teacher based in France, didn’t always like fennel. She found it overpowering and aggressively anise-forward. It wasn’t until she moved to Provence, where wild and cultivated fennel grows abundantly, that she gave the plant another shot—and moved past what she calls her “childhood trauma” around the licorice-like the flavor of fennel. 

Held was pleasantly surprised to learn how nuanced fennel’s flavors could be, depending on which part she used and how she cooked it. “Raw fennel leans heavily into the stronger anisette flavor, and any heat applied will turn even the most intense fennel into something more timid and tender,” she says.

For anise-loving, zero-waste enthusiasts like myself, it’s also extremely satisfying that the entire plant is edible. “Fennel is a remarkably versatile ingredient,” says Held. You can slice the bulbs into crisp salads or hearty roasts, muddle the stalks into cocktails, use the fronds in sweet or savory dishes, and mix the seeds into spice blends and sausages. When I’m feeling flush, I shell out for the fennel pollen at my local farmers market and sprinkle it onto grilled fish or roasted vegetables.

So, what is fennel, exactly? Here’s everything you need to know. 

What Is Fennel?

Fennel is a flowering perennial herb native to the southern Mediterranean that heavily features in Levantine, Greek, Italian, and other cuisines from the region. Its expansive family tree, Apiaceae, spans carrots, caraway, celery and its root celeriac, parsnips, lovage, parsley, and cilantro. Cooks use every part of the plant: its sturdy white bulb, pale green stalks, and the feathery fronds that sprout yellow blossoms and produce seeds and pollen. 

At farmers markets and grocery stores, fennel bulbs are often sold with their long, leafy fronds still attached. Though most fennel sold today measures six to 12 inches, the plant can grow up to six feet tall.

How to Identify Fennel

Appearance

Fennel’s white bulb is ribbed like celery and usually about the size of a tennis ball. It’s connected to hardy, light green stalks that usually measure anywhere from six to 12 inches long when sold. Darker green fronds top the stalks and, after 12 to 16 weeks of growth, may produce bright yellow blossoms. The fronds and flowers are edible, but are sometimes trimmed when the plant is packaged for sale. 

Flavor

Fennel’s potency depends on the variety. Finocchio, sometimes called Florence, is a sweet fennel that is widely cultivated and available across the U.S. It has fruity anisette notes, particularly in its bulbous base. Other Mediterranean varieties grown for their sweetly flavored bulbs include Di Firenze and Fino. Wild fennel grows throughout the Mediterranean region as well, and often features anise flavors alongside more savory, bitter notes. On most edible fennels, the bulb and stalks are crisp and mild, but are less aromatic than the feathery fronds, which have a licorice-like sweetness and lemony notes. Fennel pollen, which is extracted from the flowers and then dried, has anise flavors with honeyed citrus undertones.

Season

“The season for fennel in the U.S. depends on the region and climate,” says Amber Grossman, creator of the Instagram account Black Girls Gardening and the author of a book by the same name. In the cooler northeastern and midwestern United States, fennel is best grown in late spring to early fall, with peak harvest in late summer to early fall, she says. In the warmer southern states and parts of California, the plant thrives from November to April, before sky-high summer temperatures. Wild fennel is perennial and flourishes in many regions throughout the year, Grossman adds.

How to Use Fennel

Fennel is delicious raw and cooked, according to Jilbert El Zmetr, the chef and founder of Laziza restaurant in Brooklyn, New York. “Raw fennel has a stronger anise fragrance than its cooked cousins,” he says. Cooking it “mellows out the anise flavor and brings forward more of the natural sweetness.”

Fennel Bulb

To highlight raw fennel’s crunch and distinct anise notes, you can toss thin slices of the bulb with bitter greens like radicchio and endive in a bright anchovy vinaigrette. Or, you could bring out the vegetable’s sweetness with citrus in an arugula and fennel salad with oranges or fennel- and citrus suprème–topped avocado toast. 

When roasted or braised, fennel becomes tender and almost creamy. Layer paper-thin slices of fennel bulb and Russet potatoes beneath seasoned chicken thighs to make an easy sheet-pan supper, or use it like an allium in a hearty casserole or velvety pasta sauce. The anise notes will be understated, providing subtle sweetness to round out the savory ingredients. Cooking mellows the more potent, black licorice-adjacent notes of fennel, much like how roasted, or sautéed celeriac doesn’t immediately announce itself as part of a celery plant.

Fennel Fronds

Fennel fronds are anise-scented and taste mildly sweet and citrusy, making them a great ingredient base for a punchy pesto. They’re also wonderful with fish, such as stuffed into a whole branzino with rosemary and tangerine. You can also combine them with fresh herbs such as mint and parsley to accompany roasted red meats or mushrooms, suggests El Zmetr. At Laziza, he infuses olive oil with the bright green fronds for several days to impart the oil with a herbaceous flavor, then drizzles it onto salads.

Fennel Seeds

Whole fennel seeds are chewy with gentle spiced notes. They’re used in cooking and medicine across many cultures, from the Mediterranean to India, says Held. In many parts of South Asia, people enjoy candied fennel seeds as a breath freshener and to aid digestion. “Fennel seeds pair well with pork and fish, but, honestly? Fennel seeds pair well with most things,” says Held. “I love to use them ground up in roasted vegetables and meats of all kinds, whole in stocks and broths, and in spice mixes.” 

Use them to make a crusty herb rub for roasted pork tenderloin, or toast and mix them into sweet or spicy pork sausages. Ground fennel seeds bring earthy sweetness to spice blends like five-spice powder and garam masala, too.

What to Substitute for Fennel

The best substitutions for fennel depend on which part of the plant your recipe calls for and how it’s being cooked or used. Here are five swaps to try.

Anise seed: Anise seed is similarly sized and chewy, but it has a more powerful licorice flavor than fennel seed. To substitute it, use half as much as called for in the recipe. 

Anise liqueur: If you’re blitzing sauteed fennel into a soup or curry, you might be able to swap in a dash of anise liqueur. In this oyster stew, Daniel Gritzer, Serious Eats’ editorial director, suggests using three tablespoons of Pernod for 50 grams of diced fennel. Liqueur contains more sugar than the plant, though, so use a light hand and taste as you go.

Caraway: Caraway and fennel hail from the same family of flowering plants, Apiaceae, and have a similar anise flavor and chewy texture. Use caraway as a one-to-one substitution for fennel seeds inside fatty meat blends like sausages.

Celery: Thanks to its high water content and crunchy texture, celery is the best one-to-one substitute for fennel in raw preparations like salads. It tastes mellower, though, so adjust your seasonings to taste.

White onion: If your recipe calls for roasting or sauteing sliced fennel bulb, use an equal amount of white onion. While onion doesn’t have the exact same anise flavors, it’s similarly tender and mild-tasting when cooked. 

When You Shouldn’t Try to Substitute Fennel

When you’re garnishing a dish with fronds, you certainly can swap in different fresh herbs like parsley or dill, but they won’t have fennel’s sweet, citrusy flavors, and your meal will have an entirely different flavor profile.

Similarly, while you can use half as many anise seeds as fennel seeds in savory rubs, anise seeds may overpower aromatic spice blends like garam masala, so I’m more likely to skip them than try to find a substitute. Sometimes, only fennel will do.

How to Store Fennel

To store fennel, start by separating the bulb from any attached stalks and fronds. Keep the bulb wrapped in a kitchen towel or paper towels in the crisper drawer of your refrigerator for up to 10 days. Loosely wrap the fronds and stalks separately or store them in open plastic bags; they’ll last for five to seven days in the fridge.

Store fennel seeds in an airtight container in a cool, dry place.