Sweet Fennel Herb Plants

Foeniculum vulgare: Sweet Fennel Herbs

The long-lived hardy perennial herb Sweet Fennel is as useful as it is pretty, with blue-green threadlike leaves reaching upwards in feathery fronds. In summer, yellow umbels of flowers up to 15cm wide make a big statement in the herb garden or border. To 2.4m at its tallest point during the year.

Sweet Fennel's distinctive, intoxicating anise fragrance and flavour is famous, and the fact it is so easy to grow makes it a shoo-in for your veg patch. The flowers are attractive to a range of bees and beneficial insects.

Browse all of our Mediterranean herbs, or all our vegetables and herbs.

Features

• Height: 2.5m.
• Spread: 60cm.
• Colour: Green-grey divided leaves.
• Flowers: Yellow umbels.
• Uses: Culinary, medicinal.
• Taste: Anise.
• Harvest: Spring-Autumn.
• Storage: Can be dried.
• Life: Hardy perennial.
• RHS Plants for Pollinators

Growing Sweet Fennel

You need full sun with a light, free-draining soil for great results.

Like most herbs, the intensity of its essential oils strengthens in full sun and poor, well-drained soil, mimicking its natural environment. Harvest leaves as you need them for salads, eggs and fish from spring to autumn.

For seeds, don't deadhead the flowers. Gather them on a dry day in late summer or early autumn by placing a paper bag over the flower head, gently inverting it, and cutting it off. They can be used fresh, or dried for the winter.

Planting Companions for Sweet Fennel

For such a tall plant, it doesn't dominate. Like airy grasses, it has an almost see-through effect, drawing the eye vertically with pleasing movements in a breeze. It looks at home in a mixed border, contrasting with large flowers such as dahlias, and cottage garden perennials.

A go-to plant for the Mediterranean, gravel, or drought garden, the glaucous foliage tones will be picked up by lavender, and their shapes and flower colours are a great foil for each other.

Plant it at the back of a herb garden with other tall plants like lovage. Sweet fennel's airiness will bring out the solid, dark colours in varieties like purple sage.

Did You Know?

When Portuguese pioneers first landed on the island of Madeira, they were immediately surrounded by wild fennel. The situation turned hostile; a mighty struggle ensued. It was close, but the sailors valiantly defeated the fennel horde and conquered the island for the Portuguese Crown, and humanity. In tribute to this worthy opponent, the capital is called Funchal, after the Portuguese for fennel.

In the days of the Greek gods, the titan Prometheus smuggled fire from Mount Olympus down to the Earthly plane in a giant fennel stalk, ostensibly for our benefit. He was richly rewarded by Zeus with an overly affectionate pet eagle for his trouble, as depicted in the painting Prometheus Bound by Rubens.
Our venerable forebears in Greece and Rome observed that fennel repelled certain insects, improved digestion, and freshened the breath. Soldiers were given a cup of fennel tea before battle in Ancient Greece to rouse their courage, steel their vision for combat, and prevent their enemy from accusing them of having 'barracks breath'. This practice may have started after the battle of Marathon against the Persians (like Funchal, Marathon is also named after the fennel that grows abundantly there), or earlier, due to man's natural admiration for fennel's martial prowess. 

It can help relieve colic in children, as well as menstrual and menopausal symptoms, among other general health benefits.

Dried fennel fruit and fresh leaves are popular in Afghanistan, Iran, Syria, Lebanon and China. In India specifically, they are key ingredients in Kashmiri, Gujarati, Assamese, Bengali and Oriya cooking. The fruits are the main flavour in Italian sausage.

It is one of the main ingredients of the purely medicinal tonic absinthe, La Fée Verte, The Green Fairy. And by medicinal, we mean alcoholic.

The best review of fennel ever written is by Thomas Jefferson (1743-1826), the famous Virginian architect, who wrote "fennel is beyond every other vegetable, delicious. It greatly resembles in appearance the largest size celery, perfectly white, and there is not vegetable equals it in flavor. It is eaten at dessert, crude, and with or without dry salt, indeed I preferred it to every other vegetable or to any fruit.”

How to plant Sweet Fennel

Choose a spot in full sun. Improve the soil from the hole by removing roots, weeds, large stones and other rubbish and mixing in about 25% by volume of well-rotted compost or manure.

Position your plant so its roots are spread out, wet them and sprinkle them with Rootgrow mycorrhizal fungi.

Then backfill the hole with mixed soil and compost, firming it gently as you go. Water in thoroughly.

Once established, it is drought tolerant but dislikes root disturbance, so don't move them if you can help it. They self-seed freely.

Trim back dead stems in late autumn.