What they actually are
The Jerusalem artichoke is a North American sunflower grown not for its flower but for its tubers — irregular, knobbly lumps that sit below ground through autumn and winter, sweetening with each frost. The name is almost certainly a corruption of girasole, the Italian for sunflower; the artichoke comparison comes from a faint similarity in flavour, not from any botanical relationship.
That flavour is distinctive: sweet and nutty, with an earthy, faintly smoky quality that sets them apart from any other root you might reach for in November. They are good roasted until caramelised, puréed into soups, or sliced thin and eaten raw when very fresh.
The science behind the sweetness
Unlike potatoes or parsnips, which store energy as starch, Jerusalem artichokes store theirs as inulin — a fructan that human digestive enzymes cannot break down. It passes intact into the large intestine, where gut bacteria ferment it. This is the source of both their nutritional interest and their well-documented digestive effects, which are not a myth and should not be glossed over.
Start with a small portion and increase gradually as your gut flora adjusts. The effect diminishes for most people with regular eating. Worth knowing before you serve a generous bowlful to guests who have never tried them.
Why you find them at farm shops, not supermarkets
Those knobbles are also what keep Jerusalem artichokes off supermarket shelves. Industrial washing lines are designed for smooth, uniform produce; the irregular surface traps soil in every crevice and defies mechanical cleaning. Proper preparation requires hand-washing — time and labour that large-scale retail does not easily accommodate.
Jerusalem artichokes have therefore remained a market-garden and farm-shop crop. This suits the people growing them: varieties are chosen for flavour and yield rather than transportability, and the supply chain is short enough that tubers arrive in good condition. Look for them at farm shops, independent greengrocers and farmers' markets from late autumn through to early spring. Some growers sell them with soil still clinging on, which keeps them in better condition than scrubbed ones.
Their place in the winter calendar
The Jerusalem artichoke season runs through the coldest months, typically from around November into March, which makes them genuinely valuable in the British growing year. They bridge a long stretch of lean ground, filling the gap between the last autumn roots and the first spring growth. We have written separately about the hungry gap — that difficult period in late spring when stored crops are exhausted and new ones have not yet arrived. Jerusalem artichokes, along with stored roots and brassicas, are part of what makes that gap survivable for those eating seasonally.
The plants themselves are almost aggressively easy to grow. Perennial by nature, a tuber left in the ground will re-shoot the following year, and the plants can reach considerable height in summer before dying back. Allotment growers often use them as a windbreak. The flip side is that they are difficult to eradicate once established — any fragment left in the soil will sprout — so they repay a degree of commitment.
Choosing and keeping them
Some growers select for a smoother profile, and the least knobbly varieties are marginally easier to prepare. At the market, choose firm tubers with no soft spots or signs of shrivelling — they should feel dense, not hollow. Kept cool and dark, ideally in a paper bag rather than a sealed plastic one, they will hold for a week or two.
The skin is thin enough that many cooks leave it on entirely, particularly for roasting or soup. The flesh discolours quickly once cut, much as celeriac does, so drop pieces into cold water as you work.
