The knobbly jerusalem artichoke tubers quickly lose water when they’ve been dug up, and even when put in a polythene bag at the bottom of a refrigerator will keep firm for only up to three weeks.
The best thing is to store them in damp peat in a cool place such as a shed. That way they will stay firm throughout the winter.
For artichokes you’ve grown yourself, the best storage method is to leave them in the soil until they’re required – though you may find that slugs and woodlice will nibble one or two.
Tubers left in the ground after March will start growing – a good way to grow a new crop if you can’t eat them all in time.