Jerusalem artichokes are easy-to-grow plants that need little attention and produce a large crop of underground tubers, rather like potatoes, for harvesting in autumn and winter. A relative of sunflowers, they also send up tall stems that are topped with yellow flowers in autumn.
Jobs to do now
- Remove flowerheads
- Cut back stems to 1.5m (5ft) or stake plants
Month by month
Jerusalem artichokes are grown from tubers, rather than seeds. These are available in March and April from garden centres and online suppliers.
Choose a sunny planting site, where there is plenty of space, as these are large plants. They can also grow very tall (up to 2m/6½ft), so make sure they won’t cause problems overshadowing other crops nearby.
Prepare the soil by weeding and enriching with home-made compost. Plant the tubers 10–15cm (4–6in) deep and 30cm (1ft) apart. Just a few tubers will produce a large crop, but if you want more than one row, space them 1.5m (5ft) apart.
Tubers can also be grown in a large tub filled with good-quality compost.
When the stems are 30cm (1ft) tall, draw up a mound of soil around them, about 15cm (6in) high, to help stabilise the stems as they grow.
As these plants do grow tall, they can make a useful screen or windbreak, but they may need some support in very exposed sites. A cage made from stout stakes and strong twine is ideal. Alternatively, you can cut them back to 1.5m (5ft) in midsummer (although you’ll lose the flowers), so plants won’t be rocked by the wind, which can loosen the roots or topple the stems.
Only water in severe drought.
When the leaves start to turn yellow in autumn, cut down the stems to leave 8cm (3in) stumps. Place the prunings over the plants to keep the soil warm and make it easier to dig up the tubers in frosty weather.
Harvest Jerusalem artichokes as required from late autumn into winter, digging up the tubers using a garden fork. They don’t generally store well once dug up, so leave them in the ground until needed.
Jerusalem artichokes are persistent and will re-grow from any tubers left in the soil. So if you don’t want them coming back the following year, make sure you remove every last one.
Cooking them is simple – just scrub them clean, boil or steam until tender, then peel.
Jerusalem artichokes have a tasty nutty flavour, but they contain a carbohydrate that is not broken down during digestion and can cause wind, especially if you eat a lot at one time. Try eating small quantities to start with.
Slugs and snails
These feed on the young seedlings and you'll see the tell tale slime trail on the soil around your crop, as well as on the leaves.
There are many ways to control slugs and snails, including beer traps, sawdust or eggshell barriers, copper tape and biocontrols.
When infected by this fungal disease, plants rot at the base and a white fluffy mould may grow on affected parts.
This disease can remain in the soil for a long time, so immediately destroy any infected plants to prevent it from entering the soil. Do not compost the stems.
Nigel Slater offers a deliciously creamy seasonal recipe: artichoke soup with ginger and walnuts.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.