Belgian endive

Light and exposure

For the first phase, that of the root, Belgian endive wants full sun or generous light. The rosette of green leaves must capture as much energy as possible from May to October to build a good fleshy root, and it is that root that will feed the bud later. A shaded corner gives thin roots and a disappointing forcing.

The second phase, the forcing, takes place on the contrary in complete darkness. A cellar, a dark garage, a cardboard box turned upside down over a bin, any place without the slightest light will do. It is precisely the absence of light that keeps the endive white and mild: in the light it turns green and becomes frankly bitter.

Watering

During the growing of the root, water regularly in summer so the plant does not suffer a dry spell. A root short of water bolts faster and gives a poor forcing. Soil that stays cool, without being drowned, is the ideal from June to September.

At forcing, moisture must be constant but moderate. If you force in a bin of compost or sand, keep the substrate damp like a wrung-out sponge. In hydroponic forcing, the roots stand with their base in a few centimetres of water that is renewed. Too much stagnant water rots the collar, too little and the bud stays stunted.

Soil and repotting

For the root, aim for deep, loose, stone-free soil, rather cool and not too rich. An excess of nitrogen or fresh manure makes the roots fork and gives soft endives. Ordinary garden soil, loosened deeply, gives the best nice straight roots.

Avoid sowing Belgian endive right after a generous addition of compost: keep it for a plot that was manured the previous year. Soil too rich swells the foliage at the expense of the root, exactly the opposite of what we are looking for here.

Temperature and humidity

The root does not mind moderate cold and grows quietly all through the Belgian summer. It even withstands the first autumn frosts, which leaves time to lift it without rushing in October or November.

The forcing, on the other hand, calls for gentle, steady warmth, between 12 and 18 degrees. Below that, the bud takes far too many weeks to form; above 20 degrees it runs, loosens and opens up. A Belgian cellar holding around 15 degrees is almost perfect. It is that constant mildness in the dark that wakes the root and makes the endive grow.

Pruning and upkeep

There is no pruning in the classic sense, but two cutting gestures matter. When lifting the roots in autumn, cut the foliage about 2 to 3 centimetres above the collar, without harming the central bud, which is the starting point of the future endive. Cut too short and you damage the heart, too long and the forcing goes awry.

Also trim the tip of the roots if they are very long, so they stand upright in the forcing bin. A root of about twenty centimetres, the size of a nice carrot, is the ideal format. Roots that are too thin are discarded, they will give nothing.

Pests and diseases

In the field, watch mainly for rust and powdery mildew on the foliage in our damp summers, as well as slugs that nibble the young rosettes. Nothing dramatic in general, crop rotation and well-drained soil usually suffice.

It is at forcing that trouble really lurks. Grey mould, Botrytis, and collar rot settle in fast if the air is confined, damp and stagnant. Air out the forcing spot from time to time, never wet the heart of the endives, and remove without delay any root that starts to soften or smell, before it contaminates its neighbours.

Propagation

Belgian endive is propagated by sowing, once a year in spring. Sow directly in place from May to June, in rows spaced 30 centimetres apart, then thin out to keep only one plant every 10 centimetres. It is this thinning that decides the size of the roots, so do not neglect it.

Belgian endive is not taken from cuttings and you do not harvest its seed in the garden, because it is a biennial: it only flowers in the second year, and a forced root is eaten before that anyway. So buy fresh seed each spring, choosing a variety suited to forcing without a covering of soil, simpler for the amateur.

Month-by-month care calendar

Green Hub tips

• Absolute darkness is the key: the slightest leak of light turns the bud green and makes it bitter. An opaque cardboard box turned over the bin is enough in a cellar.
• Do not manure the plot the year of the endive. Soil too rich makes the roots fork and gives soft, loose endives.
• Stagger the forcing batches, a crate of roots every two or three weeks, to harvest fresh endive all winter rather than all at once.
• Keep the cellar between 12 and 18 degrees. Warmer, the endive runs and opens; colder, it drags on for weeks before it heads up.