Jerusalem Artichokes: Why the Tubers Can Wait in the Ground
Jerusalem artichokes need almost no care and deliver fresh tubers well into spring. Here is when to harvest and how to keep them from taking over your garden.
When the foliage of your Jerusalem artichokes turns brown, the best harvest season begins. The tubers are fully hardy and keep better in the soil than in any pantry. With a little planning you can harvest fresh for months and still keep the plant under control.
The right time
Jerusalem artichoke (Helianthus tuberosus) forms its tubers late in the year. From October, once the stems, which can reach three metres, turn yellow, you can dig the first tubers. They usually taste best after the first frosts, when part of the stored inulin turns into fructose and the tubers become mildly sweet.
The soil as your pantry
The tubers are fully hardy. You can leave them in the ground all winter and use frost-free days to dig only what you need. They taste best freshly dug, because out of the soil they quickly shrivel. In the fridge or in damp sand in a cool cellar they keep for one to two weeks.
Harvest thoroughly, or it will spread
Every tuber left in the soil can sprout in spring, even small pieces. If you don’t want Jerusalem artichokes to spread, dig over the bed thoroughly in late winter and collect every remnant. A dedicated spot at the edge of the garden or a rhizome barrier reaching about 40 to 50 centimetres deep helps. Don’t dispose of leftovers in the wild or on the compost heap, because Jerusalem artichokes readily resprout there.
Planting again in spring
Plant the tubers in March or April about 10 to 15 centimetres deep. Space them roughly 50 centimetres apart in the row and 80 to 100 centimetres between rows. The tall plants cast a lot of shade, so they are best placed on the north side of the garden or as a screen, where they won’t take light from lower crops.
In the kitchen and in your journal
Raw, roasted or as soup: the tubers taste mildly nutty. They contain a lot of inulin, a fibre that some people find hard to digest at first, so start with small portions. Note in your garden journal where the plants stood and how much you harvested. In Rootivo you can record location, harvest and observations per bed and find it all again next year.