Above: some little reject roots, too small to use. Below, the bases of the very tall stalks. To harvest Jerusalem artichokes, dig them up carefully as you need them anytime between fall and the middle of the cold season. These plants are very hardy and while a frost may damage leaves, roots are fine underground.
Sometime before the ground freezes hard, harvest all the roots and be sure to save some roots to replant for next year's crop. Replant roots immediately in rows about 1 foot apart. Jerusalem artichoke plants spread. Spring brings new growth and summer brings cheery yellow/orange flowers. A beautiful and tasty plant!