Jerusalem artichoke

Origin & history

Jerusalem artichoke is a North American sunflower that reached France at the beginning of the 17th century. Its German name comes from a misunderstanding: it goes back to the Tupinambá, a Brazilian people whose delegation caused a stir in Paris in 1613 — which has nothing to do with where the tuber comes from. In Germany it was widespread before the potato and was later grown mainly as a fodder crop; in Baden a spirit is still distilled from it today.

Varieties

Tuber shape matters more than yield: roundish, smooth-skinned varieties such as “Bianca” can actually be cleaned in the kitchen, while heavily branched types cost you half an hour every time. Red-skinned varieties like “Violette de Rennes” are more elongated and stronger in flavour. Ordinary eating tubers from the greengrocer work perfectly well as planting stock — unlike potatoes no certified material is needed, they just have to be firm and not shrivelled.

Care

The work involved is minimal; the problem is the height. The stems reach two to three metres and blow over, tubers and all, on exposed sites — a string between two stakes, or a spot along a fence where they shade nothing, solves that. Water in long dry spells, otherwise the tubers stay small and knobbly. In November cut the dead stems down but leave 20 cm standing: otherwise you will not find the row again under snow in winter.

What can go wrong

If a stand really has to go, digging it out once will not do it: clear it as thoroughly as possible in spring and then hoe off every new shoot all season until the remnants are exhausted. Voles are happy to work on the tubers in winter because they stay in the ground — fresh heaps of soil next to the row are a warning sign. Powdery mildew often coats the foliage white in late summer; a stand planted widely with air moving through it stays green longer and therefore bulks up more.

Harvest, storage & kitchen

From October only dig as much as you will use in the next few days: the skin is thin and out of the ground the tubers shrivel within a week. In the bed, by contrast, they keep all winter — in prolonged frost a layer of leaves makes digging easier. Scrubbed well they need no peeling; raw and grated they taste nutty and sweet, roasted or as soup markedly stronger. Their sweetness comes from inulin rather than starch, which is why they never turn floury when cooked.

Frequently asked questions

When do you plant Jerusalem artichokes?

Between mid-March and the end of April. Set the tubers 10 cm deep, 40 cm apart in the row and 70 cm between rows. Once planted, the clump comes back on its own every spring.

When can you harvest Jerusalem artichokes?

From mid-October to the end of March, so right through the winter. You get a full crop in the very first autumn after planting. The tubers taste best once the foliage has yellowed and died back after the first frosty nights.

Is Jerusalem artichoke winter hardy?

Yes, completely. The top growth dies down in autumn, the tubers sit unharmed in the soil and shoot again in spring, even after severe winters. That is precisely why the plant becomes a permanent resident so easily.

Does Jerusalem artichoke flower?

Yes, in September and October, with masses of small yellow blooms that look like miniature sunflowers. It does the tubers no harm — that is exactly when they bulk up. In short cool summers some varieties barely flower at all.