Growing Fennel.

Fennel is an very old plant that has it’s origins along the shores of the Mediterranean but it is now found around the world. It is often seen along roadsides and riverbanks from Australia to the USA. It has been naturalised in Britain since Roman times. Herb fennel is very aromatic with a strong aniseed like flavour. It is grown for it’s ferny leaves and seeds and has many culinary and medicinal uses. It is a main flavouring ingredient in the liqueur Absinthe. The bulb type of fennel, often called Florence fennel or Finocchio is grown for it’s swollen base and is used cooked as a vegetable or used raw in salads.

Herb Fennel [ Foeniculum vulgare ]

Soil Preparation. 

Growing herb fennel is very easy, it is a hardy perennial plant that is not fussy about soil type, so long as it isn’t too wet. Moist soil will give more lush foliage, drier conditions will give better seed production. There is a very attractive bronze variety that looks great at the back of a flower border and can be used with cut flowers. I have lots of bronze fennel in my garden, it seeds around easily and the bees and insects love it. Watch out though as it can grow over 5 feet.


You can sow inside in trays or pots of moist compost in March. Sow thinly covering with a quarter inch of compost. When about 5 – 6 inches high, plant outside in plot or border. Plant them 18  inches apart or dot around the borders. They need no special treatment while growing.


Cut the foliage to use as needed. When the seed heads have formed and start dry out, they will yellow and fade, they can be cut leaving about a foot of stem. Tie into bunches and hang up to dry in a shed or similar dry place, but out of direct sunlight. When the seed is fully dry, remove from the seed head, clean and store till needed. The fennel seed is lovely sprinkled on savoury scones or bread before baking.

Bulb/Florence Fennel [ Foenicuum vulgare: var.azoricum ]

Soil Preparation.

Growing the bulbing type fennel takes a bit more care. It is a warm soil loving vegetable so don’t sow or plant into cold soil. It likes a rich moisture retentive well drained soil. If using manure, dig it in the previous autumn/winter and add sharp sand if the soil is heavy. This will improve drainage and help the soil to warm up. Cloches can be placed over the soil to help warm and dry it.

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Early sowings can be made inside in pots or modules. Sow one or two seeds per pot of moist compost a quarter inch deep. Thin to leave one seedling. Best to keep these herb seeds indoors after sowing at a temperature of 20 – 25 Celsius for best results. Grow on, planting out after all risk of frost has passed and the soil has warmed up, this is usually from early May onwards.

If sowing outside, wait till the soil is warming up and sow direct where they are to grow. From early May sow a couple of seeds a quarter inch deep, 6 – 8 inches apart in rows 12 inches apart. When seedlings are through, they can be thinned to allow one plant every 6 – 8 inches. Further sowings can be made up to early July.


As they plants grow, they can be thinned again to leave one plant every 8 – 12 inches apart, the thinnings can be eaten in salads or lightly steamed. A feed of a comfrey or seaweed can be given every 2 – 3 weeks in the growing season. Keep the ground moist, never letting them dry out. Keep well weeded. As the bulbs start to swell, earth the soil up around the base, this will help to blanch the bulb and protect from early autumn frosts. Florence fennel does best in warm, sunny moist summers.


When the bulb is plump and ready for harvesting, carefully remove the soil from around the bulb, cut it off at ground level leaving the root in the soil. New baby shoots will grow from the root base and these can be used like the thinnings.


The biggest problem with Florence fennel is bolting. This is the plant prematurely going to seed. It is can be caused by hot dry weather, so keep your plants well watered and don’t transplant outdoor grown seedlings.


These include:  Romenesco,  Perfection,  Amigo,  Colossal.

Helen Fowler
Born in Middlesbrough. Moved to live in rural North Yorkshire in late teens. Moved back to the town in my 30's to live near Stockton on Tees. Then after a divorce and a serious accident I moved back to rural North Yorkshire near Thirsk, where I live now. I am a passionate gardener, a keen amateur photograper, I love travel, music, anything artistic and I have a great love of nature and the natural world. I have gardened since my teens and I lived and worked on a farm for years. I have owned or have experience with most pets and domestic animals. I hope by sharing my own experiences and the personal knowledge I have gained over the years, to help and encourage others to gain the most from their gardening efforts.
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