911±¬ÁÏ

Florence fennel is an attractive plant that forms a white ‘bulb’ at ground level made up of the overlapping, swollen bases of the leaf stalks. This has a sweet, mild aniseed flavour. It is also known as bulb fennel, although botanically it’s not a true bulb.

These are fleshy, rounded, underground storage organs, usually sold and planted while dormant. Examples include daffodils, tulips, hyacinths, lilies, onions and garlic. The term is often used to cover other underground storage organs, including corms, tubers and rhizomes.

bulbs

There are several varieties of Florence fennel – most are bolt resistant, which is useful if growing conditions aren’t ideal. Some varieties are more suitable for sowing earlier or later.

Look in particular for varieties with an 911±¬ÁÏ Award of Garden Merit (AGM), which shows they performed well in trials – see our list of AGM fruit and veg for recommended varieties of Florence fennel and many other crops.

If you visit the veg plots in the 911±¬ÁÏ gardens, you’ll also see many crops being grown, including Florence fennel – it’s a great way compare different varieties and pick up useful tips and inspiration.

Choose a warm, sheltered, sunny site with fertile, moist but well-drained soil.

Add plenty of organic matter, such as well-rotted manure or garden compost, ideally the winter before sowing, to improve soil structure, drainage and fertility.

Florence fennel dislikes heavy clay and waterlogged ground. If your soil is unsuitable, or you’re short on space, it can be grown in large containers, at least 40cm (18in) wide, filled with multi-purpose compost.

Fennel dislikes root disturbance, so sow seeds either direct outdoors or singly into modules indoors. Early sowings are very liable to bolt (flower prematurely), so if you want to give this a try, choose a bolt-resistant variety.

It’s best to wait until early summer (June) when sowing outdoors. Due to this late sowing time, Florence fennel is useful to fill gaps after crops such as early potatoes have been harvested.

It’s essential to keep Florence fennel well watered, to ensure it grows without any checks. It tends to bolt (flower) in dry conditions, which ruins the harvest.

Once the bulbs start to swell, mound (or earth up) soil around them to blanch them, which produces whiter bulbs with a sweeter flavour. Earthing up also helps to stabilise them and protects the bulbs from early frosts.

Florence fennel is ready to harvest in late summer and autumn, depending on sowing time. It is usually harvested when the swollen bulbs are 10–15cm (4–6in) across, but can be harvested at any size, from just 5cm (2in) upwards.

Make sure you harvest before the bulb starts to elongate and send up a flower stem, at which point it becomes woody and inedible.

To harvest, either dig up the whole bulb or slice it off just above the base with a sharp knife, leaving the lower part in the ground. This should then send up small leafy shoots that can be used in salads.

You can steam, grill, roast or braise fennel bulbs and serve with cheese sauce or butter. They have a sweet, mildly aniseed flavour and go particularly well with fish.

When using Florence fennel raw in salads, you can enhance the flavour by slicing the bulb and putting it in a bowl of water and ice cubes, then placing in the fridge for an hour.

You can also use the chopped young leaves to flavour salads and other dishes.

Fennel is best used fresh, but the bulbs can be stored in a fridge or other cool, dry place for several weeks.

The most common problem with Florence fennel is bolting (flowering), which leads to the bulb not forming or turning woody. This can be caused by various issues, including cold temperatures in spring, root disturbance when transplanting and dry conditions in summer. Florence fennel is most successful in warm, damp summers.

To deter bolting: 

• Water regularly and generously, never letting the soil dry out completely 

• Choose bolt-resistant varieties, especially for later sowings – however these can still bolt in dry or cold conditions 

• Delay sowing outdoors until early summer, and protect with cloches or fleece if temperatures dip 

• Use modular trays if sowing indoors, to reduce root disturbance when transplanting outdoors later 

• Keep early sowings indoors until the weather has warmed up, then harden off carefully and protect with cloches or fleece 

Few pests trouble Florence fennel, apart from slugs and snails, which will eat seedlings and young plants, so take steps to deter or control them. See our tips on how to stop slugs and snails.