Jerusalem artichoke is not started from seed, but from tubers.
Buy them in March and April from a garden centre or online supplier.
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.
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.
‘Fuseau’: A large, smooth-skinned cultivar, that is easy to peel.
‘Dwarf Sunray’: Long, smooth skinned tubers.
Slugs and snails: At their most active at night and after rain, they are particularly fond of new shoots and tubers of Jerusalem artichokes.
Remedy: It’s impossible to completely eradicate slugs and snails, so protect vulnerable plants. Iron phosphate-bassed pellets are the more wildlife-friendly and effective control.
Read more information on slugs
Read more information on 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.
Read more information on sclerotina