Source: RHS https://www.rhs.org.uk/advice/grow-your-own/vegetables/jerusalem-artichoke
(with minor alterations to suit southern hemisphere conditions)
This statuesque plant is a relative of the sunflower. Although it boasts attractive yellow flowers perched on 3m (10ft) stems, it is mainly grown for its below-ground tubers that can be cooked or eaten raw. Needing plenty of space to grow, this perennial is ideal when planted as a windbreak or screen.
Jerusalem artichoke is not started from seed, but from tubers.
Plant into well-prepared soil, planting at a depth of 10-15cm (4-6in) with tubers spaced 30cm (12in) apart. If you have an allotment or are particularly fond of Jerusalem artichokes, space rows 1.5m (5ft) apart. Tubers can also be grown in a large tubs filled with good compost.
When stems are around 30cm (12in) tall, draw soil around them to a depth of 30cm 15cm (6in) to help stabilise plants as they grow. Cut back stems (including flowerheads) to around 1.5m (5ft) in midsummer so plants won’t be rocked by the wind, thus avoiding the need for staking. Only water in cases of severe drought.
As these plants do grow tall, they can make an effective screen, but may need some support in very exposed and windy sites. A cage made from stout stakes and strong twine will suffice.
When foliage starts to turn yellow in autumn, prune to leave 8cm (3in) stumps above ground level. Place the prunings over plants to keep the soil warm and aid lifting of tubers in frosty weather.
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.
Remedy: There are many ways to control slugs and snails, including beer traps, sawdust or eggshell barriers, copper tape and biocontrols.
More info on Slugs and snails
Sclerotina: When infected by this fungal disease, plants rot at the base and a white fluffy mould may grow on affected parts.
Remedy: 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.
More info on Sclerotina
Harvest the tubers as required with a garden fork from late autumn into winter.
Jerusalem artichokes are persistent, so if you don’t want them coming back the following year, make sure you remove every last one – tubers left in the ground will regrow into a large plant the following spring.
Scrub and 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.
Nigel Slater uses Jerusalem artichokes in his Artichoke soup with ginger and walnuts, to make a creamy seasonal recipe.
‘Fuseau’:A large, smooth-skinned cultivar, that is easy to peel.
‘Dwarf Sunray’:Long, smooth skinned tubers.