It was a busy market day and I was standing behind my table quietly watching two customers indulge their senses by smelling all of my soaps. They picked up the last bar of “All Hallows Clean” and proclaimed, “ooh, licorice!” I smiled. After smelling a couple more bars, they picked up my Uintas bar — which has a touch of fennel in it — and said, “this one has licorice too.”

As a plant enthusiast and budding perfumer, fennel, anise, and licorice all smell very different to me. In fact, as a medicinal herbalist, I actually dislike the taste of licorice and always substitute fennel when a formula calls for it. But I love both anise and fennel. So I began to wonder — why couldn’t they tell the difference between the three?

Then I remembered the connecting constituent: anethole.

So I chimed in. “These two bars of soap don’t actually contain licorice at all,” I said. “One has fennel and the other has anise. But they both share the same basic chemical compound as licorice — anethole.” They both opened their eyes wide, as if they had just experienced a new way of seeing the world.

Why Fennel, Anise, and Licorice All Smell Like Each Other (And Why Your Candy Is Lying to You)

So what exactly is anethole, and why does it show up in three completely different plants? Anethole is a naturally occurring organic compound, a phenylpropanoid, found in the essential oils of fennel, anise, and licorice root, among others. It’s the molecule your nose is actually detecting when you catch that characteristic sweet, warm, slightly spicy scent. When three unrelated plants all produce the same aromatic compound, your brain files them under the same smell, even though the plants themselves, their flavor, their chemistry, their history, and their uses, are quite distinct.

Here’s where it gets interesting. Fennel (Foeniculum vulgare) and anise (Pimpinella anisum) are both members of the Apiaceae family, the same family as carrots, dill, and parsley. Licorice (Glycyrrhiza glabra) is something else entirely: a legume, more closely related to beans and clover than to either fennel or anise. What they share is anethole, and almost nothing else.

And then there’s the candy. Most black licorice candy contains no licorice root at all, it’s flavored with anise oil. So when people say fennel smells like licorice, they’re really smelling something closer to anise, and comparing it to a candy that was never made from licorice in the first place. It’s a case of mistaken identity three layers deep.

As someone who works closely with all three plants, I can tell you the differences are real and meaningful. Fennel is rounder, greener, almost herbaceous beneath the sweetness. Anise is sharper and more intensely aromatic. True licorice root has an earthy depth and a natural sweetness that comes from a completely different compound, glycyrrhizin, not anethole at all. But if you’ve never crushed a fresh fennel frond between your fingers or steeped anise seeds in hot water, those distinctions can be easy to miss.

That’s what my market customers experienced, not confusion, really, but the perfectly logical result of a nose that had never been given a reason to tell these three apart. Anethole does its job a little too well.

A Plant With Deep Roots: Fennel Through the Ages

Fennel is not a newcomer to human life. It has been cultivated in the Mediterranean region for at least 5,000 years, and its story winds through some of the most compelling moments in ancient history.

The ancient Greeks called fennel marathron, and the word carries more weight than most people realize. The famous Battle of Marathon in 490 BCE, where a small Athenian force famously held off the Persian army, took its name from the fennel field where it was fought. When modern runners cross a marathon finish line, they are unknowingly invoking a plant. The Greeks also associated fennel with strength, victory, and longevity, crowning successful athletes with fennel wreaths much the way we might award a medal today.

But perhaps the most striking appearance of fennel in Greek mythology is the story of Prometheus. According to myth, when Prometheus stole fire from the gods to give to humanity, he concealed the ember inside a hollow fennel stalk. The pithy interior of the wild fennel stalk smolders slowly without burning through, making it a natural vessel for carrying fire. It’s a small botanical detail that turns out to be literally true, and it suggests that the Greeks understood this plant with an intimacy that went far beyond the kitchen.

The Romans inherited much of the Greek reverence for fennel and put it to characteristically practical use. Pliny the Elder, writing in the first century CE, noted that serpents sought out fennel after shedding their skins, believing it restored their eyesight. Roman gladiators were said to eat fennel for strength before entering the arena. And Roman physicians recommended it as a digestive aid after heavy meals, a use that would echo through centuries of herbal practice right up to the present day.

By the Middle Ages, fennel had found its way into the monastery gardens of Europe, where it was cultivated alongside other medicinal herbs by the monks and healers who kept botanical knowledge alive during that period. It was considered one of the essential plants of the medieval apothecary. The deeper story of those monastic herbalists and the physic gardens they tended is one I’ll be exploring in a future post, but fennel was very much part of that world.

From the Mediterranean basin to ancient India, where it appears in Sanskrit writings as madhurika dating back to at least 2000 BCE, fennel has been a trusted plant ally across cultures and centuries. It is, in the most literal sense, a plant with deep roots.

Fennel in the High Desert Garden

Fennel loves Utah. Here in my garden, it is thriving with just one addition of compost each year. My plant is in its second year and overwintered here just fine. I cut it back to the ground in the fall, and it came right back up in the spring without any fuss.

The variety I grow is the seed type, not the bulbing kind. I let the plant grow as giant and wild as it wants to, and then I harvest the seeds toward the end of August. This year my fennel has grown to over six feet tall, and it doesn’t seem to be done anytime soon. I’m already planning to give it its own dedicated space in the garden next year so it stops crowding out its neighbors in the raised bed.

You might wonder why I grow the seed variety instead of the eating kind. The answer comes down to my herbal practice. Fennel seeds are one of the best carminatives I know, speaking from years of personal experience. I carry a small tin of them with me anytime I travel or know I’ll be eating somewhere unfamiliar, just in case my stomach has opinions about the meal.

If you frequently experience bloating, gas, or stomach discomfort after eating, a simple remedy is to chew about a teaspoon of fennel seeds slowly until they break down, then swallow. Within five to ten minutes, you should start to feel relief.

From Garden to Studio: Fennel’s Role in the Accord

Once the seeds are harvested and the fronds have done their work in the garden, fennel makes the journey into my soap studio, where it takes on a different kind of life entirely.

In perfumery terms, fennel is classified as a top to middle note. That means it’s one of the first things your nose meets when you pick up a bar, but unlike a citrus oil that brightens and disappears in minutes, fennel has staying power. It lingers into the heart of the scent rather than vanishing right away, which is part of why it works so well in a bar of soap that needs to smell good from the moment you unwrap it through the last sliver in the dish.

That sweet, anise-like brightness comes from the same anethole we’ve been talking about all along. But fennel rarely stands alone in a composition. It plays well with others, taking on the character of whatever it’s paired with while still bringing its own herbaceous sweetness forward.

I can see this clearly in two of my own bars. The Uintas bar pairs fennel with hinoki wood and benzoin, landing somewhere sweet, smoky, and earthy, like standing in a cedar grove with something warm baking nearby. Dolceacqua pairs the same fennel with lavender and patchouli instead, and the result is entirely different: floral, sweet, and grounding, more garden than forest. Same fennel, same sweetness at the core, but two completely different moods depending on what it’s standing next to.

It says something about fennel’s versatility that both bars sold out at market. People may not consciously register the anethole doing the work, but they respond to that sweetness either way, whether it’s wrapped in smoke and wood or in lavender and patchouli.

Beyond scent, fennel essential oil brings real skin benefits to a bar of soap. It’s rich in antioxidants, has natural antimicrobial and anti-inflammatory properties, and works well for those with normal to oily skin. It’s one of those rare ingredients that does double duty, shaping both how a soap smells and how it feels on the skin.

Growing Fennel in the High Desert

If you’re thinking about adding fennel to your own garden, here’s the honest truth from someone who’s growing it right now: fennel can be a bit of a bully. It loves Utah’s soil and climate, much like its native Mediterranean range and the coastal California hillsides where it’s gone wild. Give it consistent watering and it will grow large with very little effort on your part.

I started my plants from transplants picked up at a local garden center, but fennel can just as easily be grown from seed. Sow seeds about a quarter inch deep after the last frost in spring, and keep the soil consistently moist until germination, which usually takes one to two weeks. Fennel forms a long taproot early on, so it doesn’t love being transplanted once established. If you’re starting indoors, use deep pots or soil blocks so you can move the whole root system without disturbing it, or simply direct sow it where you want it to grow.

Like any self-seeding plant, fennel needs a bit of management if you want to keep it from taking over. If you’d like to control its spread, harvest the seed heads before they begin to drop. Look for seeds that are plump and full, just starting to turn a dull, light green. I harvest the entire seed head and dry it on my herb drying rack, with a bowl placed underneath to catch any seeds that fall loose during drying. If you’d rather let fennel do what it naturally wants to do, leave the seed heads on the plant to dry and self-seed for next year.

One more thing worth knowing if you’re growing fennel in the high desert or anywhere in northern Utah: native bees and pollinators go absolutely wild for the flowers while they’re in bloom. If you’re building a pollinator-friendly garden, fennel earns its place for that reason alone. I wrote more about which plants support native pollinators here.

A quick word of caution if you live somewhere with a milder, wetter climate, particularly coastal regions: fennel has become a genuine ecological concern in parts of California, where it has spread aggressively on the Channel Islands and crowded out native plants. In a dry high desert climate, it tends to stay much more manageable. But wherever you garden, it’s worth harvesting those seed heads before they drop if you don’t want fennel making decisions for you about where it grows next.

Back at the Market Table

I think about that market day often. Two customers, three plants, one shared molecule, and a moment of genuine surprise when the curtain got pulled back on something they’d been smelling their whole lives without ever questioning it.

That’s really what fennel has taught me, both in the garden and in the soap studio. It’s a plant that’s been hiding in plain sight for thousands of years: crowning Greek athletes, smuggling fire from the gods, calming upset stomachs from ancient Egypt to my own travel bag, and quietly lending its sweetness to soap bars that sell out before I’ve even finished setting up my table. It doesn’t ask for much. A little compost, consistent water, and it gives back generously, sometimes too generously, if you ask my raised bed.

The next time you catch a whiff of licorice in a bar of soap, or in a market spice stall, or even in a glass of absinthe, I hope you’ll pause for half a second and wonder which of the three it actually is. You might be surprised at how often the answer is fennel.

And if you ever find yourself at my table, picking up a bar of Dolceacqua or the Uintas soap, go ahead and ask. I love watching that moment when the eyes go wide.

Sources

Anethole. Wikipedia. https://en.wikipedia.org/wiki/Anethole

Herbs with Anise-, Fennel-, and Licorice-Like Flavors. The Herb Society of America Blog. https://blog.herbsociety.org/herbs-with-anise-fennel-and-licorice-like-flavors/

Fennel: Getting To Know Your Herbal Allies. Banyan Botanicals. https://www.banyanbotanicals.com/blogs/wellness/fennel-foeniculum-vulgare

Herbs in History: Fennel. American Herbal Products Association. https://www.ahpa.org/herbs_in_history_fennel

Fennel. Wikipedia. https://en.wikipedia.org/wiki/Fennel

Fennel. McCormick Science Institute. https://www.mccormickscienceinstitute.com/resources/culinary-spices/herbs-spices/fennel

Fennel (Foeniculum vulgare). The Sunlight Experiment. https://thesunlightexperiment.com/herb/fennel

Fennel (Foeniculum vulgare): Benefits, Safety, Uses. Herbal Reality. https://www.herbalreality.com/herb/fennel/

How to Blend with Fennel Essential Oil. VINEVIDA. https://www.vinevida.com/blogs/adhoc-aromatics/how-to-blend-with-fennel-essential-oil

Fennel in Perfumes. Fragrantica. https://www.fragrantica.com/news/Fennel-in-Perfumes-3687.html

Sweet Fennel Essential Oil: Benefits, Uses & Insights. AromaWeb. https://www.aromaweb.com/essential-oils/fennel-essential-oil.php

Native Plant Recovery in Study Plots After Fennel (Foeniculum vulgare) Control on Santa Cruz Island. Monographs of the Western North American Naturalist, BioOne. https://bioone.org/journals/monographs-of-the-western-north-american-naturalist/volume-7/issue-1/042.007.0136/Native-Plant-Recovery-in-Study-Plots-After-Fennel-Foeniculum-vulgare/10.3398/042.007.0136.full

Foeniculum vulgare Profile. California Invasive Plant Council. https://www.cal-ipc.org/plants/profile/foeniculum-vulgare-profile/

Fennel Grow Guide. Seed to Fork. https://seedtofork.com/fennel-grow-guide/

How to Grow, Harvest, and Use Fennel for Herb and Medicinal Uses. Sow Right Seeds. https://sowrightseeds.com/blogs/planters-library/how-to-grow-fennel-from-seed

Planting Guide and Seed Saving Notes for Fennel. Sow True Seed. https://sowtrueseed.com/pages/planting-guide-and-seed-saving-notes-for-fennel

The Art of Making Absinthe. Fifth Season Gardening. https://fifthseasongardening.com/the-art-of-making-absinthe

How to Make Absinthe at Home. Homebrew Academy. https://homebrewacademy.com/how-to-make-absinthe/