Chicory

About

Chicory is three crops from one species and choosing between them decides everything about how you grow it.

Witloof chicory is grown for its root in summer, lifted in November, then forced in the dark to produce the pale yellow torpedo-shaped chicons sold as Belgian endive. Radicchio and the sugarloaf types are grown for heads that stand in the garden through autumn and winter, red and white or pale green. And the wild plant, with its startling blue flowers on roadside verges, is grown as a forage crop and roasted for a coffee substitute.

Bitterness is the thread running through all of them. It is the point of the vegetable rather than a fault, and it is controlled by growing the plant cool and damp, excluding light where the type calls for it, and cutting at the right moment.

Appearance and character

A rosette of lobed leaves in the wild type and the forcing varieties, looking much like a coarse dandelion, above a long thick taproot.

Radicchio forms a tight round head the size of a small cabbage, deep wine red with white ribs in varieties like ‘Palla Rossa’, or speckled in the Castelfranco and Treviso types.

Sugarloaf chicory forms a tall pale green head like a slim cos lettuce, milder than radicchio.

Forced chicons are pale yellow to white, tightly packed and torpedo-shaped, 12 to 18 cm long, developed in total darkness so no chlorophyll forms.

Flowers are the plant’s best feature and appear in its second summer on a stem to 1.5 m: clear sky-blue dandelion-like heads that open in the morning and close by early afternoon.

Where it is from

Chicory is native to Europe, including Britain, and western Asia, growing on chalky roadsides and rough grassland.

Egyptians, Greeks and Romans all ate it, and Roman authors treated it as a vegetable and a medicine.

Forcing was discovered by accident in Belgium in the 1830s, when a farmer near Brussels left chicory roots in a dark cellar and found they had produced pale tender shoots. Witloof means white leaf in Flemish, and the technique became a Belgian industry.

Italy developed the red and variegated heading types, and Treviso, Chioggia and Castelfranco all name varieties after the towns that bred them.

Britain grew chicory for coffee adulteration on a large scale in the nineteenth century, particularly in Yorkshire, and Camp Coffee still contains it.

How it grows

For forcing varieties, sow direct in May or June at 1 cm deep in rows 30 cm apart, and thin to 20 cm. Sowing earlier causes bolting.

Lift the roots in November after the first frosts. Cut the leaves back to 2 cm above the crown, trim the root to about 20 cm, and store them horizontally in damp sand in a cool shed.

Force a few at a time from December. Plant three or four roots upright in a large pot of moist compost, cover with a second pot with the drainage hole blocked, and keep at 10 to 18 deg C in complete darkness. Chicons are ready in three to five weeks.

For heading varieties, sow in June or July at 1 cm deep in rows 35 cm apart, thinning to 30 cm. Radicchio sown before June bolts.

Cut heading types from October onwards. They stand frost and colour up better for it, and a cloche keeps them clean into the new year.

Through the seasons

Spring prepares the ground and sows nothing. Chicory sown before late May bolts almost without exception.

Early summer is the sowing window, May and June for forcing varieties and June and July for heading ones.

Summer grows the plants. Water weekly, keep the rows weeded, and resist feeding.

Autumn brings the heading types to maturity from October. Frost improves their colour and flavour. Lift the forcing roots in November after a frost or two, which is what breaks their dormancy.

Winter is the forcing season. Bring roots in from December in small batches every fortnight, so the chicons arrive over months rather than all at once. Heading types stand outside under a cloche.

Care difficulty

Moderate, and the difficulty is in the timing and the forcing rather than in day-to-day care.

The sowing date is the first thing. Late May at the earliest for forcing types and June for radicchio. Anything sown in spring runs to flower.

Forcing needs complete darkness and a steady 10 to 18 deg C. Light turns the chicons green and unbearably bitter, and any gap in the cover shows in the crop.

The cold treatment before forcing is easy to miss. Roots need a few frosts, or a fortnight in a fridge, before they will force properly.

Slugs get into radicchio hearts and are hard to reach.

Bitterness is managed rather than eliminated. Cool damp growth, prompt harvesting and darkness where appropriate all reduce it.

Watering

Water weekly through summer, around 12 litres per square metre in dry weather.

A dry summer gives markedly more bitter leaves and smaller roots, and this is the main lever a grower has over the flavour.

Water at the base rather than over the heads in autumn. Water in the heart of a radicchio overnight starts grey mould.

Keep forced roots in just-moist compost. Waterlogging rots them and dryness stops the chicons.

Mulch after thinning to hold moisture and keep the roots cool.

Container growing works for the heading types in a pot of 25 cm or more, and forcing is done in containers by definition.

Warning signs, diseases and pests

Slugs work into the heart of radicchio and sugarloaf heads and are hard to find until the head is cut. Clear the ground around the plants, water in the morning, and patrol on damp evenings.

Grey mould and bacterial soft rot brown the heart in a wet autumn. Space at 30 cm, water at the base, and remove affected plants.

Bolting follows an early sowing and cannot be reversed. Sow from late May.

Aphids colonise the heart of forced chicons in a warm dark cellar. Check the forcing pots weekly and wash them off.

Lettuce root aphid attacks the taproot, showing as wilting in dry weather and white waxy deposits on the roots. Rotate.

Green chicons mean light reached them during forcing. Block every gap.

Excessive bitterness follows heat, drought or a late harvest.

Growing environment

Full sun.

Deep, fertile, stone-free soil suits it, and the forcing types need it most because a forked root is difficult to store and force.

Neutral to slightly alkaline soil, pH 6.5 to 7.5. Chicory grows naturally on chalk.

Never sow into freshly manured ground, which forks the roots. Follow a crop manured the previous season.

A frost-free shed or cellar at 10 to 18 deg C for forcing, and it has to be fully dark.

Rotate on three years with lettuce and endive, which share the same family and several pests.

Feeding

Chicory needs very little. On ground manured for a previous crop it needs nothing.

Avoid nitrogen. It gives soft leafy heads that rot in autumn and roots that force poorly.

A dressing of sulphate of potash before sowing helps on poor sandy ground.

Never apply fresh manure.

Forced roots need no feeding at all. The chicon is grown entirely from reserves stored in the root, which is why the root is exhausted and composted afterwards.

Troubleshooting

It flowered instead of making a head. Bolting, from sowing too early. Sow forcing types from late May and heading types from June.

The chicons are green and very bitter. Light reached them during forcing. Block every gap in the cover, including the drainage hole of the covering pot.

The chicons never appeared. The roots had no cold treatment, or the shed was too cold. Lift after a few frosts and force at 10 to 18 deg C.

Brown slimy heart on a radicchio. Grey mould or soft rot in a wet autumn. Space wider, water at the base, and remove affected heads.

Slugs deep inside the head. Clear the surrounding ground and patrol on damp evenings, since by the time damage shows they are already inside.

The leaves are impossibly bitter. Heat, drought or a late cut. Water weekly, cut in cool weather, and let frost sweeten the heading types.

Can I use the root for coffee? Yes. Lift, wash, dice, dry and roast until dark brown, then grind. It is caffeine-free and tastes of roasted bitterness rather than of coffee.

Is Belgian endive the same thing? Yes. Belgian endive, witloof and chicon all mean the forced shoot of this plant. Endive proper is Cichorium endivia, a different species.