Florence fennelFoeniculum vulgare var. azoricum

Florence fennel demands the sunniest bed in the vegetable garden, sheltered from the prevailing westerly winds that flatten its tall foliage. Choose soil that stays moist without ever being waterlogged, neither a clay hollow nor a dry bank. It is happy at the edge of the greenhouse, after a spring crop such as peas or lettuces, whose soil is still clean and loose. Keep it away from beans, tomatoes and coriander, with which it gets on badly, and from dill, with which it hybridises. A row of fennel near the leeks makes good neighbours.

The bulb only forms well in light soil that is crumbly at depth. Loosen to 25 cm with a broadfork and work in three kilos of mature compost per square metre, with no fresh manure, which would give hollow, bland bulbs. In our loamy soils that compact, add a little coarse sand; in clay, build a ridge 15 cm high for drainage. Rake the surface finely, as the seed is small and the young roots fragile. Soil that is neither acid nor too chalky suits it; a handful of ash per square metre provides the potash it likes.

In our climate, sowing in place between 15 June and 15 July is the safest: the shortening days after the solstice prevent bolting. Draw drills one centimetre deep and 40 cm apart, sow a seed every 5 cm, cover with fine compost and firm with the back of the rake. Keep the soil moist with a mister until germination, in eight to twelve days. Thin first to 10 cm, then to 25 cm when the plants have four leaves; the pulled seedlings can be eaten in salad. A spring sowing under cover, in April, is possible but often bolts.

If you are set on a summer harvest, sow in mid-April or May in 8 cm pots, two seeds per pot, at 18 °C, with no more heat than that. Keep a single seedling and move the pots out under a cold frame as soon as they are up so they do not become leggy. Fennel hates having its taproot disturbed: you absolutely must plant it before the roots start circling the bottom of the pot, that is, three to four weeks after sowing. A plant that has waited in its pot, even a fortnight too long, will make a flower instead of a bulb, whatever you do afterwards.

Plant the young pot-grown plants after the Ice Saints, or in July for late sowings, in the evening, every 25 to 30 cm in rows 40 cm apart. Remove from the pot without breaking the root ball, set it so the crown is level with the surface, and firm without forcing. Water copiously, two litres per plant, then mulch lightly with dried grass clippings. That same evening, put in place protection against slugs, which adore young fennel: a cut-down bottle or a collar of ash. Shade with a crate for the first three days if the sun is strong.

Fennel does well in a container at least 30 cm deep and 40 cm wide, one plant every 20 cm, in a mix of two thirds potting compost to one third garden compost, over a bed of clay pebbles. Sow directly into the container at the end of June, a station of three seeds at each position, and keep the strongest seedling. Put the container in the sun but watch the watering very closely: in a pot, a single day of drought in August is enough to trigger flowering. A mulch over the surface and a saucer emptied after each watering give good-sized bulbs in September.

The most common fault is sowing in April in open ground, in soil at 8 °C: the fennel sulks, suffers a cold snap and flowers from June without making a bulb. The second is transplanting plants that are too old or bare-rooted. The third is forgetting to water in the middle of a heatwave. Finally, many people confuse Florence fennel with perennial wild fennel, which never makes a bulb and whose seeds self-sow everywhere. Check the packet for the words "Florence" or "azoricum" before buying.

The whole art of fennel lies in regular watering: neither dry nor drowned, but always moist. Allow eight to ten litres per square metre twice a week whenever rain is lacking, daily in a heatwave, applied at the base in the evening. The slightest water stress is read by the plant as the end of the season, and it bolts within days. A porous hose under the mulch, or an upturned bottle pushed in beside each plant, evens out the supply. Check with a finger: the soil should be moist 5 cm below the surface.

As soon as the plants are 15 cm tall, spread 5 cm of fine mulch, dried grass clippings or chopped straw, keeping the crown slightly clear. This mulch keeps the soil cool, stops our loams from capping and cuts watering by a good third. As for feeding, fennel is moderately hungry: nettle liquid diluted to 10 % once established, then comfrey liquid every three weeks once the bulb starts to form, are enough. Avoid any excess nitrogen, which gives exuberant foliage and a soft bulb that keeps badly.

When the bulb reaches the size of an egg, generally four to five weeks after sowing in place, draw fine soil or mulch up its sides to half its height, leaving the leaves clear. Repeat twice at ten-day intervals. Deprived of light, the bulb blanches, becomes more tender and less fibrous, and loses its bitterness. This earthing up also steadies the plants against the wind. Pinch out without hesitation any flower stem as soon as it shows: the bulb would stop swelling, but a plant pinched in time still gives a few weeks of leaves.

Fennel suffers little disease in our gardens. Slugs are the real danger to young plants: pick them off at dusk, turn over trap boards in the morning, and use a coarse mulch while the plants are small. Black aphids sometimes settle on the stems in summer; a jet of water in the morning or a spray of soft soap at 5 % deals with them, and the hoverflies drawn by neighbouring umbels do the rest. Rot at the crown signals soil that is too wet or earthing up done too early on cold ground. Do not replant fennel in the same spot for three years.

Mid-June, sowing in place and first protection against slugs. Early July, thinning, mulching and nettle liquid. Late July, diligent watering, first earthing up as soon as the bulb forms, comfrey liquid. August, second earthing up, watching for flower stems, picking leaves for the kitchen. September, harvest of the first fist-sized bulbs, lighter watering. October, harvest of the rest before the hard frosts; a fleece laid over the remaining plants gains two or three weeks. November, cutting the stumps to 3 cm and covering with leaves for a few leafy regrowths.

Cut the bulb with a knife just below the base plate, as soon as it is firm, white and 8 to 10 cm wide; better to harvest a little early than a little late, as the bulb hardens quickly. Harvest in the morning by preference, for crisper flesh. Leave the stump in place: it regrows as small leafy stems that flavour stocks and fish until the frosts. To spread the harvest, sow in three batches, mid-June, early July and mid-July. A layer of dead leaves and a double fleece keep the last bulbs in the ground until mid-November in Brabant or Hainaut.