🌻 Jerusalem artichoke

Despite the name, Jerusalem artichokes are neither from Jerusalem nor artichokes: they are the knobbly tubers of a tall native North American sunflower. They are very hardy, almost impossible to kill, and give a heavy crop of sweet, nutty tubers from autumn to early spring with almost no attention.

The plants grow 2–3 m tall and make an excellent windbreak or summer screen. The main caution is that they spread: every tuber left in the ground regrows, so plant them in a spot where this is welcome, such as a corner of the plot or a large raised bed.

Varieties to try

Fuseau (long, smooth tubers that are easy to clean)Stampede (early, heavy cropper)Dwarf Sunray (shorter and tidier)White Fuseau (smooth and white)

Plant tubers from February to April in any reasonably fertile soil, in sun or part shade. You can buy tubers from garden centres or use ones from a greengrocer, as they are not prone to the same diseases as potatoes. Plant them 10–15 cm deep and 30–40 cm apart, in rows about 90 cm apart.

Because they spread vigorously, consider planting in a contained area such as a large bottomless pot or a bed edged with a barrier sunk 30 cm deep. Choose a site where tall plants will not shade neighbouring crops, such as the north side of the plot, or use the plants as a windbreak.

Top tips

• Plant at the north end of the plot so they do not shade other crops.
• Even small tuber pieces will grow.
• Edge with a buried barrier if you need to limit spread.
• Mulch with compost after planting.

Jerusalem artichokes need almost no care. Water in the first few weeks and during very dry spells, and earth up the stems lightly when they reach 30 cm to improve stability. Tall plants can blow over in strong winds, so cut them back to about 1.5 m in midsummer or support them with stakes and string.

Cut off any flower buds if you want to maximise the tuber crop, though the bright yellow blooms are attractive and loved by pollinators. Slugs eat tubers, and sclerotinia and powdery mildew can affect the stems in damp summers, but severe problems are rare.

Top tips

• Cut stems to 1.5 m in midsummer to prevent wind rock.
• Remove flower buds for a bigger crop.
• Mulch to suppress weeds.
• Grow them on their own, as they are very competitive.

Watch out for

SlugsSclerotinia stem rotPowdery mildewWind damage

When the foliage has turned brown and died back in October or November, cut the stems down to about 15 cm and lift the tubers with a fork as you need them. They store best in the ground and have thin skins that dry quickly once lifted. Dig carefully, as the knobbly tubers snap easily.

Harvest through to March, then lift all the tubers so the bed does not become overrun, saving some of the smoothest ones to replant. Any small pieces left in the soil will re-sprout, so check carefully if you want to move or clear the bed.

Top tips

• Leave tubers in the ground until needed.
• Cut stems to 15 cm and use them as markers.
• Pick out every piece if you want to stop regrowth.
• Save your best tubers for replanting.

The tubers have a creamy, nutty flavour a bit like artichoke hearts. Scrub, peel if you wish, and use in soups, roasts, gratins or purées, or slice raw into salads. They are rich in inulin, which can cause wind for some people, so start with small portions and cook them thoroughly. Adding a little lemon juice keeps the cut flesh from browning.

Tubers shrivel quickly once lifted, so dig only what you need. Unwashed tubers keep for one to two weeks in a bag in the fridge, or you can store scrubbed tubers in slightly damp sand. Cooked purée and soup freeze very well.

Top tips

• Start with small portions, as inulin can cause wind.
• Roast with olive oil, garlic and thyme at 200°C.
• Add lemon juice when cutting to prevent browning.
• Make a velvety soup with stock and cream.