(Credit: Pixabay)

The Jerusalem artichoke has an identity problem: it is neither from Jerusalem nor is it an artichoke. Rather, it is a sunflower-root masquerading as a potato that packs a nutty flavor and a notorious reputation for digestion aftereffects.

Jerusalem artichoke bears compound flowers resembling those of wild sunflower. (Credit: Clemson University)

Known botanically as Helianthus tuberosus, Jerusalem artichoke is a perennial plant closely related to the common wild sunflower (Helianthus annuus). It is believed to have originated in the Ohio River and Mississippi River valleys and, therefore, is a native species in Missouri. Because Jerusalem artichoke developed in our climate, it is well adapted and easy to grow.

Some people consider this plant to be a wildflower, some call it a weed, and others think of it as a vegetable. It produces potato-like tubers that do not contain starch. Instead, the carbohydrate they contain is in the form of the inulin, of which 99% cannot be digested by humans. Most plants that synthesize and store inulin do not store other forms of such as starch.

An unfortunate side effect of consuming Jerusalem artichoke tubers involves inulin. When the undigested inulin reaches the large intestine (colon), resident gut bacteria rapidly ferment it. This rapid fermentation process releases gases—including hydrogen and methane—which leads to flatulence, bloating, and sometimes cramping.

Boiling the tubers of Jerusalem artichoke reduces their inulin content. (Credit: Wikipedia)

Parboiling sliced tubers in water with lemon juice or vinegar triggers acid hydrolysis, breaking down the stubborn inulin into simpler, digestible sugars before they are eaten. Additionally, eating small portions consistently helps your gut microbiome adapt, reducing severe digestive reactions over time.

The caloric content of fresh Jerusalem artichoke tubers is very low. During storage, some of the inulin converts to fructose, a simple sugar that can be metabolized by humans. This makes the caloric content of the tubers rise, although it still is quite low. One hundred grams of tubers contains only 75 calories.

Native Americans cultivated Jerusalem artichoke about 400 to 500 years ago. Champlain, an early American explorer, considered the flavor to be like that of globe artichoke (Cynara cardunculus var. scolymus). Yet its name is misleading. When Jerusalem artichoke tubers were introduced into Europe in 1612, they became popular in the Mediterranean region as food for both humans and animals. There, the plant was called "girasole articiocco" which vaguely described the plant as articiocco (an old Northern Italian dialect word for the globe artichoke) and girasole (the Italian word for sunflower, or one that turns to the sun). Over time, the name girasole was corrupted by English-speakers to Jerusalem. As previously mentioned, the plant has nothing to do with Jerusalem and is not closely related to globe artichoke.

Jerusalem artichoke grows quite tall and often achieves a height of between six and twelve feet. Its stout stems support leaves that are rough and hairy. It bears compound flowers known as capitula (heads). The petals (ray florets) are yellow giving the flower the appearance of a small sunflower. Its roots are fibrous with knobby tubers at the ends of rhizomes. Tubers usually are white to cream in color, but there also are red and purple types.

Tubers of Jerusalem artichoke normally are white, but red/purple types are available. (Credit: Clemson University)

Although Jerusalem artichoke has been grown for hundreds of years, it has never developed into an important food source. Its tubers are not a substitute for potatoes, since their flavor is different. Inulin does not react in the same way as starch when cooked. Instead, cooked tubers tend to be waterier. Raw tubers may be eaten raw in salads and have the consistency of water chestnuts. They also may be baked or cooked, and pickled.

Greatest tuber production occurs during the autumn when sugars are moved from the leaves to the roots. The tuberous roots survive Midwest winters quite well. Therefore, there is no rush to dig them in the fall. Although some could be harvested in late September or early October, it is best to wait to harvest the majority of the crop until after the first hard freeze. Since tubers must be refrigerated after they are dug, most gardeners allow them to remain in the soil and harvest as needed during the winter. The application of thick layer of mulch after the tops have died back keeps the soil from freezing and makes winter harvesting easier.

Since Jerusalem artichoke spreads aggressively, care should be taken when selecting a planting site. (Credit: Pixabay)

Under very good soil and environmental conditions, Jerusalem artichoke can become an invasive weed. Unless you are very careful, refrain from planting them where the soil is tilled or plowed, since tillage can spread the tubers or pieces of them. Tubers are best planted in an open area that is surrounded by turf than is mowed. Jerusalem artichoke does not tolerate mowing and can be contained using that tactic. Plant firm, healthy tubers 4 to 6 inches deep and 12 to 18 inches apart in loose, well-draining soil during early spring.

To eliminate established beds, plow or deep till the area frequently during May, June and July. This practice depletes the reserves of existing tubers and prevents the formation of new ones. The downside is that no other crops can be grown in that area either. Jerusalem artichoke also can be killed with herbicides but repeat applications will be needed in many cases.

Even though this plant may spread rapidly in good garden soil, there is no reason not to plant it. Jerusalem artichokes are an excellent addition to the garden because they are incredibly hardy, low-maintenance perennials that provide an abundant harvest of delicious, nutrient-rich tubers every autumn while producing beautiful, sunflower-like blooms all summer.